Select * from EMP;
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Program to prove that Data set is connections less Collection of tables XML based
Using System. Data. Sql client;
Data Set ds = new Data Set ();
Code for Button 1_click (get)
{
Sql connection con = new Sql connection (“User id = sa; Password = ;
data base = north wind; Server = local Host”) ;
Sql Data Adapter d1 = new Sql Data Adapter (“Select * from products” , con);
Sql Data Adapter d2= new Sql Data Adapter (“Select * from orders ” , con);
D1.Fill (ds, “pr”); D2.Fill (ds,”or”);
Message Box. Show (“Data is ready”);
Code for Button 2_click
(products)
DS----Tables or 1
{
Data Grid view 1. Data Source = ds . Tables [“Pr”];
or ds. Tables [0];
}
Code for Button 3_click (orders)
{
Data Grid view 1. Data Source = ds. Tables [“or”];
or ds. Tables [1];
}
Code for Button 4_click (XML)
{
Ds. Write XML (“C: //abc.XML”)
Message Box. Show 1 (“File is created”);
} 25 columns
Note:- Oracle client namespace is not available at the default scope of the project, hence System. Data. Oracle client Assembly needs to be added.
Add reference System. Data. Oracle clientUsing System. Data. Oracle client
Static oracle connection con = new oracle connection (“User id = Scott; Password = tiger ”);
The provider is not required for a managed connection.
Oracle Data Adapter da = new oracle Data Adapter (“Select * from c 194”, con);
Data set ds = new Data set (); Code for Button 1_ click (get) Da. Fill (ds, “d”);
Data Grid view 1. Data Source = ds .tables [“d”];
Code for Button 2_click (save) Oracle command builder cb = new; Oracle command builder (da);
Message Box. Show (cb. Get Insert command () )
Da. Insert command = cb. Get Insert command ();
Da. Update (ds, “d”);
Message Box. Show (“Record is Added ”) ;
} A collection of Data set Related classes is called “Data Set class Hierarchy”.
DS T1000 records
[179] [N] FIRST N =0;
LAST N = DS. Tables [‘T’]. Rows . count -1 Next N = N+1 Previous N = N-1 A program for navigating through the records
Code in GD Data table dt = new Data Table ();
Int n =0 ;
Public void Show record ()
{
Data Row dr = dt. Rows [n];
Text Box1.Text = dr [0]. To String ();
Text Box2.Text = dr [1]. To String ();
}
Code for Form 1_ load Event Sql Connection con = new sql Connection (“User id = sa; data base = north wind; Server = Local Host”);
Sql Data Adapter da = new Sql Data Adapter (“Select * from Products”, con); Data set ds = new Data set (); Da. Fill (ds, “d”);
Dt = ds . Tables [“d”];
// column Names Label 1 .Text = dt. Columns [0]. Column Name;
Label 2 .Text = dt. Columns [1]. Column Name; Show Record ();
}
{
N =0; Show Record ();
}
Code for Button2_ click (< Previous record )
{
N = n -1; If (n== -1) { Message Box. Show (“No previous Record ”);
N = 0;
}
Show Record ();
}
Code for Button 3_click (> Next Record)
{
N = n+1;
If (n > dt. Rows. Count -1 )
{
Message Box . show (“ No Next Record”);
N = dt. Rows. Count -1;
}
Show Record ();
}
Code for Butto4_ click (>> last Record)
{
N = dt. Rows . count – 1;
Show Record ();
}
Project Menu Add Reference System .wed (this is required for Mail Message class) Place Timer (System .Timers )control Properties Enabled = true Interval = 60, 000 Interval 100ms w:30 12:30:00 01 1 sec = 600 .. 100ms = 60 … 1 60,000 59 60,000
Using System. web. Mail;
Code for Timer 1 _ Elapsed Event
{
Int sh =Date Time . Now. Hour ;
// 24 hrs format
Int sum = Date Time . Now. Minute;
If (sh == 12 && sm ==30)
{
Mail Message m = new Mail Message ();
M .to = “teja @ yahoo.com”; m.cc = “varoon @india.com”;
subject = “Happy Pongal”;
body Format = Mail Format. Html;
body = <h1>Happy pongal </h1> <hr>
<h2><Font color = Green> Dear Friends, This is to inform you that, our next class will be on 17th jan, 2009 </Font> </h2>”;
Form = “Prakash @ptpl”;
//ptpl is computer name Smtp Mail .Send (m);
}
// if6 1/2 Avenue, Manhattan's street
(416)-528 369
Rathod@gmail.com.
Bachelor of Engineering in Information technology, Brenau University, Washington.
3 years of experience in software developing applications at Australia New Zealand Banking Group.
It is a specification for interacting with any database or XML documents.
Base class library (BCL):
It is a collection of rich class library definitions that can be used from any application developed using any language targeting the .NET
Note: .NET achieves language independence with the support of CTS & BCL.
CLR: It is a collection of resources which are used for executing a .Net application within a .Net environment
In C language: If we execute first .exe in c o/p will get directly
In .NET Tech: If we execute first.exe in .Net the o/p will not get directly so it must be passed through CLR for O/p
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Executable file: Whenever an application can be executed by the DS without any support of external runtime environment or tools then such types of applications are called Executable File. 
Metadata: It is used to maintain the information about the header files that are used within the application.
Code: The code present within the executable code is a machine and platform-dependent format and hence the native platform can understand the code.
X86 Instruction Set: It maintains the complete platform details which are needed for the execution
Observation: An executable file provides the complete information which is needed for the OS for execution and hence no additional runtime environment is needed.
Assembly: The compiled source code of any .Net application can be considered as an assembly.
Note:
Metadata [Data about Data]:
It maintains the information about BCL, CL (base class library, class library), and dependency file information within the application
Ex: In C 
Header files
MSIL code: The compiled source of any .Net application developed using any language will be in the format of MSIL instructions which is a platform and a machine-independent format code.
Resources: It maintains the information about resources which are used in the application like audio-video clips, images, icons, cursor, fonts, etc.
Manifest: It is used to maintain the information about the attributes of an assembly such as author name, company name, version of the application, etc.
Observation: An assembly provides the details about itself but the information which is needed for the operating system will not be provided and hence the assembly cannot be executed directly by any OS. PEWRAPPER: [Portable Executable WRAPPER] It is used to invoke CLR for the execution
CLR: It is a collection of resources which are used for executing .Net application within the .Net environment
Executing the project under the client system, copy the project folders into the system from the cd.
Open sql server2005 data base files folder
We will find two data base files
“ERES-Data ”and” ERES-log”
Copy these two files into c:program filesMicrosoft sql server/ms sql/data.
goto sql server2005 management studio Startàrun àprogram
sql server 2005
Double click
We will be getting a wizard
Server type: Data base Engine Server name: Run
cmdàhost name
sys2
Login:sa
Password:123
Authentication SQL Server Authentication
Connect
Select databasesvRight clickattachclick
Add buttonselect PSA-Data mdfàDouble click
ERES
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OKàSymbol will be displayed
Admin
Consultancy people will be using ERES and conducting the test.
Administrator(User)
Candidates registered
Subject details and Question bank details
Experience
Psychology test
ASP.NET and vb.net
Manual evaluation
Registration number(Consultancy) Profiles Languages Skills
Asp.net questions(blocked)
Recruiters, consultancy
candidate Registration
Reports means total number of candidates appeared
9 modules in the project
Time Restriction.
Candidates login
DFD
How the data is flowing from one module to another module. Subjects data base
Enrollment is registration. 2 to 3 level
Water fall model Spiral model RAD model
Waterfall model
11:T3cad,
Thread means process
Pentium iv 4.3 GHZà43 Lakhs of instructions(cycle ) within 1min Speed
Ctrl+ Alt+ del
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DOS UNIX
given to one app only
System. Threading namespace
Class test {
Public vaid print(){}
}
Syntax:-
Test t = new test();
Thread start ts=new thread start(t.print);
Thread tr=new thread(ts);
Start the thread Tr. start()
A program to execute two for loops simultaneously
Open console application project Using system. Threading;
code in GD Class test
{
Public static vold p1()
{
For (int i=1; i<=10;i++)
{
Console. write(I+””);
Thread . sleep(500);
}//for
}
//p1
Public static void p2()
{
For(int k=11;k<20;k++)
{
Console. write link(k);
Thread. sleep(500)
//500 millisec
}//for
}
//p2 }//test
Code for the main method:-
Thread start ts1=new thread start (Test.p1)
Thread start ts2=new thread start (Test.p2)
Thread t1=new thread (ts1)
Thread t2=new thread (ts1):
//here
ts1 T1.start() T2.start() Console.Read key();
T1.suspend(); Console. Read key();
T1.Resume(); Console. Read key ();
o/p : 112233----2020
1.Thread synchronization is the concept of allowing only one thread at a time into one process
2.It process is busy, threads need to wait in the queue
3.Waiting threads will be executed based on priority
OBS:
5.The code which is written in between wait one()and release mutex()is called a synchronized code.
{
Console. write(“ALL”);
Console. write(“THE”);
Console. write(“Best”);
}
open console application project Using system. Threading;
Class program
{
Static mutex m = new mutex();
Class test
{
Public static void print()
{
wait one();
console. write(“ALL”);
Thread. sleep(1000);
Consote. write(“THE”);
Thread .sleep(1000);
Console. write(“BEST”);
Thread. sleep(1000);
Console. Write line();
//for new line Thread. sleep(1000);
Release mutex();
}//print }//test
Code for the main method:-
{
Thread start ts=new thread start(test. print);
Thread start t1=new thread (ts);
Thread start t2=new thread (ts);
Thread start t3=new thread (ts);
T1.Start(); T2.Start();
T3.Start();
Console. Read key();
}
Pointers:-
Why we use pointers? For fast accessing Fig(a) Accessing ’i’ value is fast when compared to the pointer variable, but it is not in this case fast. Char*p
2B Double*p
Logic is m/c of o/s they are unmanaged code.
The size of the pointers varies or dependent on the o/s, so they are unmanaged code, so c#.net only supports pointers but not implemented.
Unsafe is a keyword Pointers logic must be the part of the unsafe block only Pointer size varies from o/s to o/s Generally o/s are divided into 3 types 
Unmanaged code is not all recommended In c# .net it we want to use in c# by using un sate keyword
Ex:-
Place a button on the form
{
Un sate { Int iz 90; Int*p; P=&I;
Int k; K=*p**p; MBS(K+””);
}
By pressing f5 it gives a warning that you are using un state code. Please inform to CLR to execute unsafe code.
Go to project
properties
buildàCheck Menu “Allow un sate code” Check Box Execute the project Inter+ view
Internal look-Behavior
subject
time sense
Body language
confidence
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Place a button on the form
Code for Button1-click
{
Var x = 1500;
Message box. show(X. Get Type().name);
}
Property Auto Implemented property
Data type var name; Public data type Property name Public
Data type pname {
{
set” (no logic) Set{var name - value Get:
Get{return var name} }
}
Auto implemented property is a collection of set and get methods without any logic.
Auto implemented property are required for object initializes and collection initializes.
Class em {
Private int double SQL, Eno;
Public string e name;
Public emp(int){}
Emp E1= new Emp(id)
P Emp(string x){}
Emp E2= new Emp(‘Teja’) (double x)…
Emp E3 = NEW Emp(71.3) Emp
E4 = NEW Emp(101,teja)
------- =
NEW Emp()
EMP E1=new EMP(101,”Teja”);
4.Syntax to create an object with object Initialize EMP E1=New EMP{Property name=value} Auto Implemented property 5. The main objective of the object Initializes to reduce the number of lines in the source.
Code
Place a button on the form
code in GD Class emp
{
Public int eno
{
set;get;
}
Public string ename
{
set; get;
}
Public int SQL
{
set; get;
} }//Emp
{
Emp E1 New EMP{Eno=101, Ename=”Bangaru”, SQL=5000};
Message Box.show(E1.Eno+””+E1.Ename+”” E.SQL);
} 
Int x; Int[] x= new int[10]
EMP[]X=new EMP[10]; //Orcate an array with 10 elements but not with 10 objects If we want 10 objects.
Example
Place a button
Code in GD Class EMP { Public int Eno {set; get;} Public string Ename{ set; get;} }//Emp
{
List<Emp>x=new List<Emp>
{
New Emp {Eno=101,Ename=”Teja”},
New Emp {Ename=”ravi”},
New Emp {Eno=203},
}//print the data For each
(EMP e1 in x) Message Box. Show (e1.Eno+””+e1.Ename);
}
Var x=new
{eno=101,ename=”teja”}
Message box. show(x.eno+””+x. ename);
Class form1 { Class test{} Inline class }//form1 Class best{} outline class
Adding a new method to an existing data type int
Open windows forms application project
Place a button
Code after form1 class { } }
//form1 Static class test
{
Public static void print(this int1)
{
Message box. show(i+””);
}//print method
}
//test
code for button1-click
{
Int x =10;
print();
} Partial class test { Partial void print(); } Partial class test { Partial void print() { Message box. Show(“from print”); } Public void display { PRINT(); }
place a button on the form
code in GD Partial class test
{
Partial void print();
//declaration
}
Partial class test
{
Partial void print();
//default private
{
Message box. Show(“from print”);
}
Public void display
{
PRINT();
}
}//test
Code for button1-click
{
Test t = new test();
display();
}
(a) Shapes (b) Graphics (c) Allows to use brushes (d)Transformations (e)Animations
XAML is similar to XML Syntactically.
| HTML | XML | XAML |
|
To describe the data | To develop WPF Applications |
|
case sensitive | case sensitive |
|
Structured Language | Structured Language |
|
Collection of user defined tags | Collection of pre defined tags |
<peers> Root element
<student>entity <sno>101
</sno > sub entities <sno> taja</sn> (or)
Attributes
</stu>
<faculty <FN>Ravi</FN>
<SAL>3800</SAL>
</Faculty>
</peers>
<Window>
<GRID>
<Button>------< /Button >
<Label>------< /Label >
< /GRID >
</Window>
Open WPF Application project.
Write the following with in Grid tag.
< Grid >
<Text block text=”MICROSOFT”>
<Font size=”40” Font family=”Arial”>
<Text block. Fore ground>
<Linear Gradient brush>
< Gradient stop offset=”.1”color=”Red”/>
< Gradient stop offset=”.3”color=”yellow”/>
< Gradient stop offset=”.5”color=”blue”/>
< Gradient stop offset=”.8”color=”Green”/>
< / Linear gradient brush>
< / Text block. Fore ground>
< / Text block >
< / Grid >
Obs:-
offset value must be in between 0 to1.
offset indicates the color starting point.
<Grid>is called a container.
WPF Supports two types of containers GRID Container
Example on Grid with multiple rows and columns
Open WPF
Write the following within Grid tag
<Grid>
<Grid. Row Definitions>
<Row Definition Height=”150”>
</ Row Definitions>
</Grid. Row Definitions>
<Grid. Column Definitions>
< Column Definitions width=”150”>
< /Column Definitions>
</Grid. Column Definitions>
<Button Grid. Row =”o” Grid. Column=”o”>Click1< /Button >
< Button Grid. Row =”o” Grid. Column=”1”>Click1< /Button >
</Grid>
</Grid. Row Definitions>
<Row Definitions Height=”150”>
</ Row Definitions >
Working with brushes
WPF supports 4 types of brushes
Solid color Brush
Linear Gradient Brush
Radial gradient Brush
Image Brush
Technology
Open WPF Application project Remove Grid tag and type canvas Type the following within canvas tag.
<canvas>
<Ellipse width=”200”Height=”200” Stroke=”Red” Stroke Think news=”5” Canvas. top=”20”canvas.left=”40”>
< Ellipse. Fill>
<solid color brush color=”blue”>
</solid color brush>
< /Ellipse>
< Elliple. Fill>
< /Convas>
< Ellipse. Fill>
< Linear Gradient brush>
< Gradient stop offset =”2” color=”Blue”/ >
< Gradient stop offset =”4” color=”yellow”/ >
< Gradient stop offset =”6” color=”Red”/ >
< Gradient stop offset =”7” color=”Green”/ >
< Gradient stop offset =”9” color=”Orange”/ >
< /Linear Gradient brush>
</ Ellipse. Fill>
(or) <Radial gradient Brush>
</Radia L Gradient Brush>
Example on Image Brush
open WPF Application project
ViewàSolution ExploreràRt click on project Name
AddExisting ItemChoose an image Type the following within grid tag
<Grid>
<Text block Text=”Microsoft” Font family=”Arial” Font size=”200”>
<Text block. fore ground>
<Image brush Image source=”Sybset.jpg”>
</Image brush>
</Text block. fore ground>
</text block>
</Grid>
Working with wpf transformations
Trans formation is the concept of moving an object in a particular angle
WPF Supports 3 types of transformations.
Rotate transformation
Skew Transformation
Scale transformation
<control>
< control. Render Transform>
<Rotate Transform . . . . ./>
</control. Render Transform >
</control>
Obs Transformations must be the part of render transform tag.
Open WPF Application project
Replace Grid tag with canvas
< canvas>
<Button width=”100”Height=”60” Convas. Top=”30” Convas. Left=”20”>
click
<Button. Render. Transform>
<Rotate Transform Angle=”45”>
<Rotate Transform>
</Button. Render. Transform>
</Button>
</ Convas >
The syntax for skew Transformation
<Skew Transform Angle x =”50”>
Angle y =”20”></skew Transform >
<canvas> <Button width=”100”Height=”60” > <Scale Transform scale x=”2” scale y=”2”></ scale Transform >
<canvas>
<Control---------->
<Controls. Triggers>
<Event Trigger------>
<Begin story board>
<Story board>
<Double Animation -------->
</Story board>
</Begin Story board >
</Control. Triggers>
</Control>
</Control>
àOpen WPF Application project. Replace Grid with canvas tag top
<canvas>
Ellipse /
<Line x1=”10” y1=”10”x2=”50”y2=”10” Stroke=”RED” Stroke Thickness =”5”> X:Name =”abc”>
Line object name
<Line. Triggers>
<Event Triggers Routed Event= “Convas. Loaded”>
<Begin story board>
<Story board >
<Double Animation Story board . Target name=”abc” Story board Target property=”(canvas. left)” From = “o” To =”800”>
Auto reverse =”True” Repeat Behavior=”Forever” Duration=”00:00:03”>
</Double animation>
</ Story board >
</Begin story board>
</Event Trigger>
</Line. Triggers>
</Line>
</Canvas>
Working with LINQ[Language integrated Query]
C#.NET
Oracle Int[]x=new int[]
Works on tables {7,5,8,2,7,6,1}
All the records From I in x
select I; Select*from emp: select I;
Select*from emp: Where SQL>1000; >5 From i in x where i>5 Select i;
Sorting
SQL Ascending order
From I in x order by I
select * from emp Ascending select I;
order by SQL ASC;
SUM(),Average(),MAX(),Min() etc.
Open windows form application project
place a button
Code for Button 1-click
{
Int[]x=new int[]{4,6,2,6,8,9,1,3};
Strings=””;
//print the values which are>5 Var v=from I in x where i>5 select I;
//Sort the numbers in ascending order.
Var v = from I in x order by I ascending select I;
//printing distinct numbers
Var v=(from in x select i)Distinct();
//printing the sum of the numbers
Int total=x.sum();
Message box. show(total+””);
//Printing the arrange of the numbers
Double total =x. average();
Message box. show(total+””);
For each(int k in v) S=s+k+””;
Message box. show(s);
Place one more button(button2)
code for button2-click
{
Int[]x=new int[]{4,6,2,6,8,9,1,3};
Strings=””;
//print the values which are>5 Var v=from I in x where i>5 select I;
//Sort the numbers in ascending order.
Var v = from I in x order by I ascending select I;
//printing distinct numbers
Var v=(from in x select i)Distinct();
//printing the sum of the numbers
Int total=x.sum();
Message box. show(total+””);
//Printing the arrange of the numbers
Double total =x. average();
Message box. show(total+””);
For each(int k in v) S=s+k+””;
Message box. show(s);
Example: LINQ With a data set
Open windows form application project place a button and a data grid view Using system.
Data. Sql client;
Code for button1-click
{
Sql connection cn = new sql connection (user id=SQ;
Password=;database=north wind; Server = Local host” );
SQL Data Adapter da=new Sql data Adapter (“Select*from products”,cn);
Data set ds= new dataset(); Da. fill(ds, ”d”); Data table dt=ds. Tables[“d”];
Innumerable<data Row>ie=dt. as Enumerable();
IQuery able<data row>dr=i.e. As Query able();
Dr=from I in dr select I;
Dr=from I in dr where i[“Product name”]. To string()==”chai” select I;
Dr=from I in dr where int. parle(i[“product id”]. To string())<5 select I;
Data grid viewl. data sources= dr. copy to data table();
}
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Else
{
Message box. show(“not Admin”);
new form().show ();
}
Execute the project then roles.Exe will be created under D:c194Rolesbindebug.
DEPLOYMENT:-
(1)Windows XP 
Main() { If(“Hi”);
Source code
}
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In the above diagram the copied exe file will be executed successfully in the client machine I,e the project is deployed successfully Same diag
}
i.e, No License need to be purchased.
File new project other project Types Setup and Deployment Setup wizard template.
Obs:-
Roles.exe file will be created under D:C194 RolesBinDebug Folder
(This name will be displayed in welcome screen)
3.Then a wizard will be opened
W1) Click next
W2) Select “Create a setup for a windows application” and click next.
W3) Add the files like*.txt,*.jpg,*.xml etc, If required then click next
W4) Click on finish
Build the project(Build menuà Build solution)
S:-Roles based security.msi and stup.exe files are created under
c194roles based security/debug folder
Only these two files need to be given to the client
Export grants(yes/no):yes>
Export table data<yes/no: yes>
Compress extents(yes/no): yes>
C:oracleora90Bin>imp d:abc.dmp
15:T57de,
Generally distributed programming is required to develop3- Tier or N- Tier architectures.
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Ex:-
HTTP---80 SMTP---25 FTP-----31 Web logic Servers-----7070,8080,9090
In order share the Logic, Some Reouree files need to be copied from the server machine into the client machine.
Step1:- Write an interface with a set of abstract methods and compile into a DLL file.
Step2:- Write a server program by overriding Interface methods and Reserve a channel over a PORT.
Step3:- Write a client program to create a connection with server and call interface methods.
Step4:- Start server then start client programs
Obs:-
The interface DLL must be copied into both server and client machines.
Open oracle software and create a table with name users and with two columns used and pwd
Create table users(Usid varchor2(20), Pwd varchar 2(10));
Add two records as follows Insert into users values(‘teja’, ’abc’); Insert into users values(‘Ravu’, ’xyz’);
Save or commit;
Open class Library project with the project name Middle Interface. Namespace middle Interface { Public interface MI { Bool check user(String a, String b); }//HI }Middle Inter face
Build the project(build menu
Build solution)
Obs:- Middle interface.dll is created under D:/C194/ Middle interfaceBinDebug folder
Open console Application project with project name Middle server
project menuàadd referenceà System. Runtime. Remoting
Project menuàAdd referenceàbrowseà Middle Interface.DLL
Using system. Run time. Remoting;
Using system. Run time. Remoting. channels;
Using system. Run time. Remoting channels. TCP;
Using system. Data. oleDb;
Code in GD(Before Main)
{
Class M Server: Marsha L By Ret object, HI
{
Public bool check user(String a, string b)
{
String q=” select* from users where Usid=’”+a+”’ and pwd=’”+”’;
oleDb connection cn = new oleDb connection (“user id = scott; password= tiger;provider=msdaora.1”) Cn.open();
oleDb command cmd= new oleDb command(q.cn); object obj=cmd. Execute scalor();
H(OBJ==NULL) Return false; Else Return true;
}//check user method }//m server-class àcode for
main()
{
TCP channel t= new TCP channel(1600);
Channel Services. Register channel(t);
Remoting configuration. Register well known service type (type of (m server),”abc”, well known object mode Single call);
Console. write line(“server is ready to use”); Console. Read key();
}Execute the project Then a TCP Server will be created with the following URL Tcp://Local host:1600/abc
open a new .NET Window(startàrunàdevenr)
open WFAP with project name Middle client
Project menuà Add ReferenceàBrowseà Middle Interface.DLL
Design the form as shown
Using middle Interface;
code for button1-click
{
MI X=(MI)Activator. Get object(type of(MI)”tcp://Local host:1600/abc”);
BooL B= X. Check user (text box1.text,Text box2. text);
If(b==true) Message box. show(“valid user”);
Else Message box. show(“not a valid user”);
}
Obs:- Remoting configuration. Register well-known service type() takes3 arguments
Org 1) Type of the class, where interface methods are over rided .
Org 2) Provide an alias name to the server
Org3) Specifies the mode of the communication Remoting supports two types of communication model with the help of well-known object mode enum 
Single call is tastes in communication when compared with single ton
In single call, a separate object will be created for every client
In single ton, only one object will be created for all the clients When number of clients are limited then use single all other wise use single ton Activator class is used to open a connection with my specified URL 2 Developing an application like yahoo messenger with off line support and two consecutive messages quid not be same
Open class library project with project name yahoo Interface
{
Public Interface YI
{
String Get TEXT();
}
}
Build the project(Build menuBuild solution)
Yahoo Interface.dll is created under D:C194/Yahoo Interface/Bin/Debug folder
Open windows farms Application project with project name yahoo server
Design the form as follows:-
Project
Add Reference
System. Run time. Remoting
project menu
Add Reference
Browe
Yahoo Interface.DLL
Using system. Runtime. Remoting;
Using system. Runtime. Remoting. channels;
Using system. Runtime. Remoting. Channels.TCP;
Using Yahoo Interface;
Code in GD
Static string S;
Class y server: Marshal By Ret Object.YI
{
Public string Get text()
{
Return Farm1.s;
}//Get Text
}//4 Server
Code for Button1-click(send)
{
Forml. s=text box2.text;
}
Code for farm1-load Event
{
TCP Channel=new TCP Channel(4829);
Channel Services. Register channel(t);
Remoting configuration. Register well known Service type(type of (4 Server),”yahoo”, well known object mode. single ton);
Text box1.text=”server is Ready”;
}Execute the project
Then a tcp server will be created with the following URL Tcp://Local host:4829/yahoo
Developing client application
Open a new .NET Window
Open WFAP with project name yahoo client
Place two text boxes, one button, and a timer control with enabled = false
Project menu
Add referenceBrowseYahoo Interface.dll
Using yahoo Interface; code in GD String s1,s2; YI X;
code for the formal – Load event
{
X=(YI)Activator. Get Object(type of (yI) “tcp://Local host:4829/yahoo”);
Text box1.text=x. get text();
Timer1.Enabled=true;
}
àcode for time:-1-tick event
{
S1-X.Get Text();
If(s1 !=s2)
Text box1.text=text box1.text+ Environment. new line+s1;
S2=s1;
}F5
Which is an abstract class.
AS per the above observations, all types of connection classes will be having the same method names and same property names.
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Con. open (); Con . close (); Con. Open ();
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DDL: create, alter, drop DML: insert, delete, update TCL: commit, rollback, savepoint QL: select Stored Procedure is a collection of SQL Statements.
Properties:-
Execute Reader () returns Data reader.
EMP
ENO ENAME SAL
1 Ravi 5000
1000 Select * from EMP ;
Execute Reader () ALL
Execute Scalar () ALL
17:T1acc,
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Step 1. Write a class with a method
Syntax:-
Class Test {
Public void Print ()
{
logic ;
}
}
Step 2. Create a Delegate
Syntax :- public delegate void D name ();
Step 3 . create an object for the delegate with the address of a method.
Syntax :-
Test t = new Test ()
D name d = new D name (t. print);
Step 4. Call the Delegate
Syntax :- d ();
Example on SCD :-
{
Class Test
{
Public void Print ()
{
Console .Write (“From Print”);
}
}
//test
Public delegate void D name ();
Code in main ()
Test t = new Test ();
D name d = new D name (t. print);
D();
Console. Read Line ();
OBS:-
Delegates encapsulate some information like class name and method names.
OBS:
D6= D5 – D3 – D2 = GM GA - GM GA - GA = GM
Class Test
{
Public void M1 ()
{
Console . Write (“GM ”);
}
//M1
Public void M2 ()
{
Console . Write Line (“GA”);
}
//M2
}
// Test
Public delegate void XYZ ();
Static void Main (Strings [] args)
Code in main ()
{
Test t = new Test ();
XYZ = d1, d2, d3,d4,d5,d6;
D1 = new XYZ (t. M1);
D2 = new XYZ (t.M2);
D3 = d1 + d2; Console. Write line (“From D3 :”);
D3 ();
D4 = d3 +d3;
Console. Write line (“From D4 :”);
D4 ();
D5 = d4- d1;
Console. Write line (“From D5:”); D5 ();
D6 =d5-d3-d2;
Console. Write line (“From D6 :”);
D6 ();
Console. Read line ();
}
101 teja 5000
102 raviteja 2000
102 Ravi xyz
103 ravi 6000
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C/S Architecture
Managed connections work with the help of the TDS (Tabular data String) Protocol.
Unmanaged connections work with the help of OLEDB(object linking and Embedding Databases ) provides.
Group 1:-
common namespace
Group 2:-
Unmanaged Name Spaces 4.System. Data. OLEDB (Supports all type of databases)
Group 3:-
Managed Namespaces
Group 4:-
ODBC Namespace
Group 5:-
LINQ Related Name Spaces
EX 1:- With oracle over Unmanaged connection
A procedure to find provider names automatically.
“one. UDL” and close it File name extension universal data Linker
Using System. Data. Oledb;
Code for Button 1 _click
{
Oledb connection con = new oledb connection
(“User id = Scott ; password = tiger; provider = msdaora.1”);
Con. open ();
Message Box .show (“Connections is ok”);
String q = “Create Table c 194 (Eno number, E name varchar 2 (10), Sql number)”;
Oledb command cmd = new oledb command (q, con);
Try {
cmd. Execute Non query ()
Message Box. Show (“Table is created ”);
}
Catch (oledb Exception oe)
{
Message Box. Show (oe. Message e );
} 
Insert into c 194 value (101, ‘Teja’, 5000)
String s = “Insert in to c 194 values (“ + text box1.Text + “, ‘ “ + text box2. Text + “, ‘ “ + text box 3.text +”)”;
Message Box .show (s); Oledb _connection con = new loedb connection (“provider = ms da or a.1 ; user id = scott; password = tiger “);
Con. Open (); Oledb command cmd = new oledb command (s, con);
cmd. Execute Non query (); Message Box. Show (“Record is added”);
}
Ans:.NET Framework is a complete environment that allows developers to develop, run, and deploy the following applications:
.NET Framework also enables a developer to create sharable components to be used in distributed computing architecture. NET Framework supports the object-oriented programming model for multiple languages, such as Visual Basic, Visual C#, and Visual C++. .NET Framework supports multiple programming languages in a manner that allows language interoperability. This implies that each language can use the code written in some other language.
Ans: .NET Framework provides enormous advantages to software developers in comparison to the advantages provided by other platforms. Microsoft has united various modern as well as existing technologies of software development in .NET Framework. These technologies are used by developers to develop highly efficient applications for modern as well as future business needs. The following are the key components of .NET Framework:
Ans: The following are the new features of .NET Framework 4.0:
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Ans: Intermediate Language is also known as MSIL (Microsoft Intermediate Language) or CIL (Common Intermediate Language). All .NET source code is compiled to IL. IL is then converted to machine code at the point where the software is installed, or at run-time by a Just-In-Time (JIT) compiler.
Ans: Assembly metadata is stored in Manifest. Manifest contains all the metadata needed to do the following things
The assembly manifest can be stored in a PE file either (an .exe or) .dll with Microsoft intermediate language (MSIL code with Microsoft intermediate language (MSIL) code or in a stand-alone PE file, that contains only assembly manifest information.
Ans: Code contracts help you to express the code assumptions and statements stating the behavior of your code in a language-neutral way. The contracts are included in the form of pre-conditions, post-conditions, and object-invariants. The contracts help you to improve-testing by enabling run-time checking, static contract verification, and documentation generation.
The System.Diagnostics.Contracts namespace contains static classes that are used to express contracts in your code.
Ans: The following two new classes are introduced in the System. Numerics namespace:
Ans: Managed extensibility framework (MEF) is a new library that is introduced as a part of .NET 4.0 and Silverlight 4. It helps in extending your application by providing greater reuse of applications and components. MEF provides a way for the host applications to consume external extensions without any configuration requirement.
Ans: Memory-mapped files (MMFs) allow you to map the content of a file to the logical address of an application. These files enable the multiple processes running on the same machine to share data with each Other. TheMemoryMappedFile.CreateFromFile() method is used to obtain a MemoryMappedFile object that represents a persisted memory-mapped file from a file on disk.
These files are included in the System.IO.MemoryMappedFiles namespace. This namespace contains four classes and three enumerations to help you access and secure your file mappings.
Ans: CTS is the component of CLR through which .NET Framework provides support for multiple languages because it contains a type system that is common across all the languages. Two CTS-compliant languages do not require type conversion when calling the code written in one language from within the code written in another language. CTS provides a base set of data types for all the languages supported by.NET Framework. This means that the size of integer and long variables is the same across all .NET-compliant programming languages. However, each language uses aliases for the base data types provided by CTS. For example, CTS uses the data type system. int32 to represent a 4-byte integer value; however, Visual Basic uses the alias integer for the same; whereas, C# uses the alias int. This is done for the sake of clarity and simplicity.
Ans: Side-by-side execution enables you to run multiple versions of an application or component and CLR on the same computer at the same time. As versioning is applicable only to shared assemblies and not to private assemblies, two applications, one using a private assembly and the other using a shared assembly, cannot be stated as side-by-side executables.
Ans: The System.GC.Collect() method.
Ans: CLR uses the Dispose and Finalize methods to perform garbage collection of run-time objects of .NET applications.
The Finalize method is called automatically by the runtime. CLR has a garbage collector (GC), which periodically checks for objects in heap that are no longer referenced by any object or program. It calls the Finalize method to free the memory used by such objects. The Dispose method is called by the programmer. Dispose is another method to release the memory used by an object. The Dispose method needs to be explicitly called in code to dereference an object from the heap. The Dispose method can be invoked only by the classes that implement the IDisposableinterface.
Ans: Code access security (CAS) is part of the .NET security model that prevents unauthorized access of resources and operations, and restricts the code to perform particular tasks.
Ans: Managed code is the code that is executed directly by the CLR instead of the operating system. The code compiler first compiles the managed code to intermediate language (IL) code, also called as MSIL code. This code doesn't depend on machine configurations and can be executed on different machines.
Unmanaged code is the code that is executed directly by the operating system outside the CLR environment. It is directly compiled to native machine code which depends on the machine configuration. In the managed code, since the execution of the code is governed by CLR, the runtime provides different services, such as garbage collection, type checking, exception handling, and security support. These services help provide uniformity in platform and language-independent behavior of managed code applications. In the unmanaged code, the allocation of memory, type safety, and security is required to be taken care of by the developer. If the unmanaged code is not properly handled, it may result in a memory leak. Examples of unmanaged code are ActiveX components and Win32 APIs that execute beyond the scope of native CLR.
Ans: Tuple is a fixed-size collection that can have elements of either the same or different data types. Similar to arrays, a user must have to specify the size of a tuple at the time of declaration. Tuples are allowed to hold up from 1 to 8 elements and if there are more than 8 elements, then the 8th element can be defined as another tuple. Tuples can be specified as a parameter or return type of a method.
Ans: YOU can use the Code Access Security Tool (Caspol.exe) to turn security on and off.
In the .NET Framework 4.0, for using Caspol.exe, you first need to set the <LegacyCasPolicy> element to true.
Ans: Garbage collection prevents memory leaks during the execution of programs. A garbage collector is a low-priority process that manages the allocation and deallocation of memory for your application. It checks for the unreferenced variables and objects. If GC finds any object that is no longer used by the application, it frees up the memory from that object.
GC has changed a bit with the introduction of .NET 4.0. In .NET 4.0, the GC.Collect() method contains the following overloaded methods:
GC.Collect(int)
GC.Collect(int, GCCollectionMode) Another new feature introduced in .NET is to notify you when the GC.Collect() method is invoked and completed successfully by using different methods. The .NET 4.0 supports a new background garbage collection that replaces the concurrent garbage collection used in earlier versions. This concurrent GC allocates memory while running and uses current segment (which is 16 MB on a workstation) for that. After that, all threads are suspended. In the case of background GC, a separate ephemeral GC - gen0 and gen1 can be started, while the full GC - gen0, 1, and 2 - is already running.
Ans: There are two key concepts of CAS security policy- code groups and permissions. A code group contains assemblies in it in a manner that each .NET assembly is related to a particular code group and some permissions are granted to each code group. For example, using the default security policy, a control downloaded from a Web site belongs to the Zone, Internet code group, which adheres to the permissions defined by the named permission set. (Normally, the named permission set represents a very restrictive range of permissions.)
Assembly execution involves the following steps:
Ans: Following are the differences between namespace and assembly:
Ans: A piece of managed code is executed as follows:
Ans: Use the GC.SuppressFinalize() method to suppress the finalize process inside the garbage collector forcibly in .NET.
Ans: The following are two ways to instantiate a tuple:
Tuple<String, int> t = new Tuple<String, int> ("Hellow", 2);
Tuple<int, int, int> t = Tuple.Create<int, int, int> (2, 4, 5);
Ans: System.Object is the root namespace for fundamental types in .NET Framework.
Ans: The CAS mechanism in .NET is used to control and configure the ability of managed code. Earlier, as this policy was applicable for only native applications, the security guarantee was limited. Therefore, developers used to look for alternative solutions, such as operating system-level solutions. This problem was solved in .NET Framework 4 by turning off the machine-wide security. The shared and hosted Web applications can now run more securely. The security policy in .NET Framework 4 has been simplified using the transparency model. This model allows you to run the Web applications without concern about the CAS policies.
As a result of security policy changes in .NET Framework 4.0, you may encounter compilation warnings and runtime exceptions, if your try to use the obsolete CAS policy types and members either implicitly or explicitly. However, you can avoid the warnings and errors by using the <NetFx40_LegacySecurityPolicy> configuration element in the runtime settings schema to opt into the obsolete CAS policy behavior.
Ans: The .NET Framework is shipped with compilers of all .NET programming languages to develop programs. There are separate compilers for the Visual Basic, C#, and Visual C++ programming languages in .NET Framework. Each .NET compiler produces an intermediate code after compiling the source code. The intermediate code is common for all languages and is understandable only to .NET environment. This intermediate code is known as MSIL.
Ans: Lazy initialization is a process by which an object is not initialized until it is first called in your code. The .NET 4.0 introduces a new wrapper class, System.Lazy<T>, for executing the lazy initialization in your application. Lazy initialization helps you to reduce the wastage of resources and memory requirements to improve performance. It also supports thread-safety.
Ans: Memory management in the CLR is divided into three generations that are build up by grouping memory segments. Generations enhance garbage collection performance. The following are the three types of generations found in a garbage collector:
Ans: In .NET 4.0, the CLR supports covariance and contravariance of types in generic interfaces and delegates. Covariance enables you to cast a generic type to its base types, that is, you can assign an instance of type IEnumerable<Tl> to a variable of type IEnumerable<T2> where T1 derives from T2. For example,
IEnumerable<string> str1= new List<string> ();
IEnumerable<object> str2= str1; Contravariance allows you to assign a variable of Action<base> to a variable of type Action<derived>. For example,
IComparer<object> obj1 = GetComparer()
IComparer<string> obj2 = obj1; .NET framework 4.0 uses some language keywords (out and in) to annotate covariance and contra-variance. Out is used for covariance, while in is used for contra-variance.
Variance can be applied only to reference types, generic interfaces, and generic delegates. These cannot be applied to value types and generic types.
Ans: The following are the different ways to assign a value to a complex number:
Bypassing two Double values to its constructor. The first value represents the real, and the second value represents the imaginary part of a complex number. For example,
Complex c1 = new Complex(5, 8); /* It represents (5, 8) */ By assigning a Byte, SByte, Intl6, UIntl6, Int32, UInt32, Int64, UInt64, Single, or Double value to a complex object. The assigned value represents the real part of the complex number, and its imaginary part becomes0. For example,
Complex c2 = 15.3; /* It represents (15.3, 0) */ By casting a Decimal or BigInteger value to a Complex object. For example,
Complex c3 = (Complex) 14.7; /* It represents (14.7, 0) */ Assigning the value returned by an operator to a Complex variable. For example,
Complex c4 = c1 + c2; /* It represents (20.3, 8) */
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1a:T4248,
A program, which is under the control of windows OS is called as Windows Service.
Ex:- Timer, Event log, File System Watcher
File NewProjectVisual C # Windows Windows Service project template.
Note:- Windows Service project template is available in Professional Edition. it is not available in Standard Edition.
(a) On Start () will be executed when service is about to start. (b)On Stop () will be executed when service is about to stop.
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Start Settings Control panel Performance and Maintenance Administrative tools Services (or) Start Run Service. MSC
Step 1: Open windows service Project Template and write the code as required.
Step 2:- Add the installers and build the project to get an Exe file.
Step 3: Install the exe file with the help of INSTALLUTIL TOOL.
Step 4: Open Service and start the service
Develop a service to restrict the accessibility of calculator software, if the user trying to open the calculator then display a message like “ Your System is effected with virus Please shut down”
OBS:-
Open windows service project with project name WSI
Add Reference Windows.FormsAdding Timer Control into tool Box.
Open Tool Box
Right click inside of General Tab
choose Items
Timer (System. Timers) Place Timer in Windows service with Enabled = false;
Using System. Windows.Forms;
Code for Timer 1_ Elapsed event
{
Process [] p = process . Get Process ();
For (int I = 0; I < p. length; I ++)
{
If (p [i].Process Name . To Upper () = = “CALC”)
{
P[i].KILL();
Message Box.Show (“Your System is effected with virus please shutdown”);
Break;
}
}
//for Code for On Start ()
Event
{
Timer 1.Enabled = true;
}
Code for On Stop () Event
{
Timer 1.Enabled = false;
} 
Build the Project (build menu Build Solution )
OBS:-
WS1 .exe is created under D: / C194 / WS1 / Bin/Debug folder with a Service called as ABC 1 Installing the Service Open.net command prompt Debug > install util – I ws1.exe The transacted install completed Service is installed with the name ABC 1 Staring the service Open Service (Start run service.MSC)
Properties login check “Allow Service to interact with desktop” checkbox okNote:- This step is required only when Service Contains a Message box.
StartAdding Installers:-
Open Service 1. Cs [Design]
Right-click inside the body
Add Installer
OBS:-
Two controls will be added Service Process Installer
Properties Account = Local System Service Installer properties Service name = abc 2 Build the project (Build build Solution) OBS:- Ws2.exe is created under D: / C 194 /ws2/bin/Debug folder with a Service called as ABC 2 Open.
Net command prompt Change to D:/c 194 /ws2/bin/Debug folder Install Util – I ws2.exe Open service (Start run services.msc) Sight click on ABC 2 start Then check C:/INET PUB/mail Root/Queue folder for a mail at 12:30
To access the service, a service controller class is required, which is the part of the Service process Assembly. Methods of the service controller class
Project Menu Add Reference System. Service Process
Using System. Service Process;
Code for GD Service Controller [] x;
Code for Formal_ load event
{
X = Service Controller . get Service ();
For (int I = 0; I < x. length; I ++)
List Box1.Items .Add (x [i]. Service. Controller);
}
Code for start button
{
Int I = list box1. Selected Index; X [i].Start ();
}
Code for stop button
{
Int I = list box1. Selected Index;
X [i].Stop();
}
(Or)
X [I = List Box 1. Selected Index] .Stop ();
That is the assembly developed in C #.net can be used in Vb .net and ASP.net also and vice versa.
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Go to project menu Add reference Browse choose a DLL file
System. DATA System. DATA. OLEDB
Note: - To develop assemblies .net introduced class library project template
Note:- DLL files are not executable, only it contains reusable code.
For every project, by default, a namespace will be created with the name of the project.
Namespace private e test
{
Public class test
{
Public string M1 ()
{
Return “form M1”;
}
//M1
}
//test
}
Namespace sub private Test
{
Public class test 2
{
Public String Print ()
{
Return “from print”;
}
//print
Public string PRINT ()
{
Return “from PRINT”;
}
//print
}
//test2
}//sub private test
}//private test Build the project (build menu build solution)
Private test. DLL is created under D:/C194 /private test / bin / debug folder with the following Structure
Similar to System. Io
Add reference Browse private Test .dllUsing private test;
both should be returned if one write, Using private test. Sub private Test;
then only that namespace classes all user
// code for button
{
Test t = new test ();
Message Box . show (t. M1());
Test 2 S = new Test 2 ();
Message Box . show (S. Print ());
Message Box . show (S. Print ());
}
When the project is executed then private Test. DLL is copied into C :/c 194/Ctest/Bin/debug folder, hence private Test. DLL is a private assembly.
open vb.net windows Application Project with name V Test.
Project Menu
Add reference
Browse
Private Test.
DLL Place a button Imports Private Test
Imports Private Test. Sub Private Test //code for b1_click Dim t As New Test Message Box (t1. M1()) Dim S As New Test2 Message Box (S. print ())//can not be called.
Note: - Test 2 is having two methods with name print and PRINT where the only case is different. This type of method is not accessible from VB.net because VB.net is not case sensitive.
C:/Windows/Assembly
GAC – Global Assembly cache
Sn – K abc.snk Small case
Gacutil -I dll file
-u uninstall
Namespace ABC 123 { Public Class Test { Public String Get Test () { Return “from get text”; }//get text }//text }//ABC 123
(Start Programs Microsoft Visual Studio 2008 Visual Studio Tools visual Studio 2008 command prompt ) D: enter key
Abc 123 >cd bin Abc 123/bin > cd debug
OBS:-
Abc.snk file is created with a strong name linking abc.snk in the current project Project menu
Abc 123 Properties
Signing
check the “Sign the assembly” checkbox
Select “browse” from the combo box
choose ABC.snk file
Project menu
ABC 123 Properties
Application
Click on the Assembly Information button and type some information.
Build the project (build build Solution)
OBS:-
ABC 123. DLL is created under D:/c194 /ABC 123 / Bin /Debug folder Open .net command prompt and type as follows Gacutil – I abc 123.dll
OBS:-
ABC 123. DLL is registered with GAC (C :/windows/Assembly) hence it is called as shared Assembly.
Open windows Forms Application Project with Project name WINTEST Project menu
Add reference
Browse
Abc 123.dll Place a Button Using ABC 123 Namespace WINTEST
Code for Button1_click
{
Test t = new Test ();
Message Box. Show (t. Get Text ());
}
Execute the Project (f5)
ABC123.DLL is not copied into D :/ c194/WINTEST/bin /Debug folder, hence Abc 123.DLL is a Shared Assembly
All predefined assemblies are shared assemblies
1c:T1ef4,
Try
{
Int s = int Parse (t1. text)
S = S + 1000;
MBS (S + “”);
} EX: - Syntax errors
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5.To work with exception handling .net introduced 4 keywords Try, Catch, finally and throw
Try{ --- --- --- -- }
Catch (Type of exception obj)
{ }
Catch (Type of exception obj)
{ }
Finally
{ }
Exception class Hierarchy
File not formatted exception
Invalid formatted exception
{
Try
{
Int S = int . Parse (text Box1.Text)
S =s + 1000;
Message Box. Show (“Salary is ” + s);
String [] X = new String []
{
“C #”, “VB”
};
Message Box. Show (X [0]);
Message Box. Show (X [1]);
Message Box. Show (X [2]);
}
//try Catch (Format Exception fe)
{
Message Box. Show ( fe. Message);
}
Catch (Exception cd)
{
Message Box. Show (ed. Message );
}
Finally
{
Message Box. Show (“From finally”);
}
Methods of directory class
Directory. Get Logical Drive () à returns all drive names. Directory. Get Directories (path) à returns all directory names. Directory. Get Files (path) à returns all files names.
String [] X = Directory . Get Logical Drives ();
For (int I = 0; I < x. length ; I ++)
Combo Box 1. Items . Add (X [1] )
à Code for combo Box 1 Selected Index changed event
List Box 1.Items . Clear ();
String P = Combo box 1. Selected Item . To string ();
Try
{
String [] x = Directory. Get Directories (p);
For (int I = 0; I < x. length ; I ++)
List box1. Items a Add (X[i]);
}
Catch (Io Exception)
{
Message Box. Show (I .e Message) ;
}
The difference between Keypress and Key down:
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properties Back Color = black Auto Size = false Location = 202, 440 Left, top
Properties Image = Select an image Size mode = Stretch image Location = 13, 200 Left, top
{
Int I = (int) e. keycode;
//Message Box. Show (I + “”);
If ((I = = 37) && Label1.left > 0 )
Label 1.left = Label1.left -3;
If ((I = = 39) && Label1.left < this. Width - 100 )
Label 1.left = Label1.left +3;
}{
Picture Box. Top = Picture Box 1. Top – 15;
If (Picture Box. Top < 0)
{
Timer 1. Enabled = false;
Timer 1. Enabled = true;
}
Code for Timer 2 _ Tick Event
{
Picture Box1. Top = Picture Box 1. Top +5;
Picture Box2. Left = Picture Box 1. Left +1;
If (Picture Box1. Top = Label1.Top && Picture Box1.left >Label1.left && Picture Box1. Left < Label1.right )
{
Timer 1.enabled = true;
Timer 2.enabled = false;
} 
2.Every item will be identified with a unique index number which tarts always from zero.
Properties:-
used to add items at design timeMethods: -
Example on combo box:-
A program to change the shape of a FORM
Namespace System Drawing. Drawing 2 D
properties Items = add
Graphics path g = new Graphics path ();
Int I = combo box 1. Selected index;
If (I = = 0) //circle
else if (i ==1 ) //ellipse
else //triangle {
} 
Action on control is called an “Event”.
In C #. Net, always events take two arguments
Always the first argument will be an object but the second argument type may vary from event to event. C #.net events are divided into 4 groups
Mouse Related events
Focus Related events
Drag Related events
Key Related events
Mouse Related Events
Click
Double click
Mouse up
Mouse Down
House leave
House enter
Mouse More
Mouse Mover: this event will be fired when the mouse pointer placed on the control for some time.
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A program to use the company logo as the mouse pointer
Open windows form Application Project
Place a picture Box control àproperties
Image = Select an Image.
Size Mode = Stretch Image
Code for Form1 Mouse More Event
{
Picture Box 1. Location = new Point (e. x, e. y);
Cursor . Hide ();
}
Developing Animated Text
Open Windows Forms Application Project
Form àProperties àBack color = Black
Place a button
Place a Timer with Enabled = false
Using System. Drawing.Drawing 2D Code in GD
String S = “MICRO SOFT TECHNOLOGIES”
Font f = new Font (“Arial ”, 50);
Linear Gradient Brush b = new Linear Gradient Brush
(new point (100, 100), new Point (200, 300), color. Red, color .yellow );
Int x =5; Graphics g;
// abstract class
Code for Button 1_ click
{
g = this .create Graphics ();
Draw String (S, f,b 10,10);
Timer 1. Enabled = true;
}
Code for Timer 1_Tick event
{
X = X+3;
If (X > 300) X= 0;
Linear Gradient Brush b1 = new Linear Gradient Brush
(new point (100, 100), new Point (x, 300), color. Red, color .yellow );
);
draw String (S, f,b, 10, 10);
Leave: This event will be executed while the cursor is coming out from control.
Enter: This event will be executed while the cursor is Entering into control.
Note:- Generally these events will be used in Data Validations
Open Windows Forms Application Project
Place two Labels and two text boxes as shown
Place error Provider control àProperties àBack Style = Always Blink
Code for Text Box1 Leave Event {
If (text Box1. Text = “”)
Error Provider1. Set Error (text Box 1,” Eno should not be Empty “);
Else Error Provider1. Set Error (text Box 1,” “ .);
// No Space
}
Error Provider1. Set Error () takes two arguments
Arg 1: The control Name, after which a blinking Icon needs to be displayed.
Arg 2: Error Message, if this is empty, then blinking Icon will Will not be displayed.
C # supports four Types of Drag Related Events
To work with Drag Related Events, ALLOW DROP property must be set to true.
Example: -
A program for dragging the data from MS – word into .net text box.
Open WFAP Place a text box - - > properties - - > Allow drop = true Multiline = true scroll bars = both
Code for Text Box 1 Drag Enter Event
{
If (e. data. Get data present (Data Formats .Text) == true)
{
String s = (String) . e. Data . Get Data (Data Formats. Text) ;
Text Box 1.Text = s;
}
else
Message Box. Show (“Not valid”);
Class Test: Form
{
}
Test form name
Formpredefined class
Developing a user-defined from at the run time.
open windows form application project
place a button
code in GD
Class Test: Form
Code for Button 1_ click
Test t = new Test ();
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Then except form, the border and controls body remaining port will be displayed fully transparent.
Generally, Screen saves are.SCR files, which will be under c:/windows/system 32 folder Open windows forms application project with project name Abcd (output file will be abcd. exe)
Form properties (F4) and set Back color = black Form border style = none. Window state = maximize
propertiesimage = select an Image enabled = true{
X = x +5;
If (x > 400) X = 0;
Picture box 1. Location = new point (x, x);
}
{
Application .Exit ();
}
Execute the Project (F5)
Abcd .exe file will be created under
D:/c 194/abcd/bin/debug Folder
Rename Abcd .exe with Abcs.Scr
copy Abcd .Scr in to C :/windows / system 32 folder; Then check box desktop properties
Screen saver
Context menu Strip :
Display an Icon in Systems along with context menu strip.
Example:-
àOpen windows form Application project àPlace five text boxes and two buttons
Code for button 1 _ click
{
This. Back color = color .Green ;
}
à code for button2_ click (clearing the text boxes)
{
For each (control c in this. controls)
{
If (c. Get type (). Name == “Text box”)
text = “”;
} Accept Button = Button 1
Cancel Button = Button 2
20:T274e,
String S = “String /n ;
String /n………..” Write (“abc”);
Write (“xyz”);
Abc xyz
File Edit Format Help
New Select All Fonts Help topics
Open Cut Colors About
Save Copy
Print Paste
Exit
The following controls are required to develop a notepad
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propertiesMultiline = true
Dock = fill
Scrollbars = both
Allow drop = true
Right click on new set Image choose an image
Right click on cut properties short cut key
{
Using System . Io;
Using System . Drawing .Printing
}
Code for new menu Item (double click on new)
{
Text Box1. Text = “”;
}
Code for open menu Item
{
Open File Dialog 1. Show Dialog ();
String p = Open File Dialog 1. File Name;
Message box. Show (p);
Stream Reader sr = new Stream Reader (p);
Text box 1 .text = sr. Read To end ();
Sr. close ();
}
Code for save menu item
{
Save File Dialog 1. Show Dialog ();
String p = Save File Dialog 1 .File Name;
Stream Writer sw = new Stream Writer (p);
Sw. Write (text box1. text);
Sw. Flush ();
Sw. Close ();
}
Code for Print
{
Printer Setting ps = new Printer Settings ();
Print Dialog 1 .Printer Strings = ps;
Print Dialog1. Show Dialog ();
}
Code for exit {
Application .Exit ();
}
Code for Select ALL
{
Text box1.Select ALL();
}
Code for cut
text box 1.cut ();
text box1.copy ();
textbox1.paste ();
Font Dialog1.Show Dialog (); Text box 1. Font = font Dialog1. Font;
{ Color Dialog1. Show Dialog (); Text Box 1.fore color Dialog1. Color; }
{
Label L =new label ();
Dock = Dock Style .Fill ;
Font = new Font (“Arial”, 20)
Text = “ Type Help messages here” ;
Form f = new Form ();
control S .Add (L);
Show Dialog ();
}
View menu Solution Explorer right-click on my note (project name) add à new itemAbout box and provide the name test
Code for About
{
Test t = new Test ();
Show ();
}
An abstract is a keyword
When a class is not providing full functionality as per the requirement to declare that classes as “Abstract”.
A method without a body is called an “Abstract method”. Abstract methods is also called Rules.
When a class contains at least one Abstract method, then the class must be declared as “Abstract method”.
that is Abstract class contains methods with Body and methods with our body also, then these are called “partial Abstract class”.
All Abstract methods must be overridden in the derived classes. An abstract class provides a set of Rules (Abstract method), which must be followed (override) in derived classes.
An abstract class is not insatiable (an object cannot be created), but a reference can be created.
Test t = new test ()
// object
Test x;
//reference
‘t’ contains its own memory but ‘x’ does not contain its own memory.
Always reference work based on child class memory.
Shape s = new circle ();
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Open windows form application project. Place a button Code in GD
Abstract class shape
{
Private int x = 10;
y = 20;
Public void print ()
{
Message Box . Show (X + “” y);
}
//print
Public Abstract void find area ();
}
//shape
Class circle : shape
{
Provide int r = 10;
Public override void find area ()
{
Double x = 3.14 * r* r;
Message Box. Show (“Area is ” + X);
}
// find Area
Public void Display ()
{
Message Box. Show (“thanks”);
}
}
//circle àcode for Button 1_ click
Private void button1 _ click (object sender, event prgs e)
{
Circle c = new click ();
print ();
find Area ();
Display () ;
Shape s = new circle ();
print ();
find area ();
}
The interface is similar to Abstract classes.
The interface contains only abstract methods.
The interface supports a structure like multiple inheritance Syntax to write an interface
Interface int name
{
Void read (); à CLR-àpublic abstract àvoid Read ()
Void Print ();
}
All interface methods are by default public abstract methods.
Partial class Test
{
Programmer 1
}
Partial class Test
{
Programmer 2
}
“Partial” is a keyword.
When a class needs to be implemented in multiple locations with the same class name, then their classes need to be declared as partial classes.
Example of Interface and Partial classes
Open windows form Application project Place a button Code in GD
Interface i1
{
Void read ()
}
Interface i2 :i1
{
Void Print ();
}
Partial class test : i2
{
Public void read ()
// overriding method
{
Message Box. Show (“From read”);
}
}
//Test Partial class T
est // : i2 not must
{
Public void Print ();
{
Message Box. Show (“From print”);
}
}
//test *F5 Code for Button 1 _ click
{
Test t = new Test ();
read ();
print ();
i2X = new Test ();
read ();
print ();
*F5
Inheritance is a concept of deriving the features from one class to another class.
An inheritance leads to code reusability.
Inheritance also saves memory.
Observation
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Class EMP
{
P in temp no (or) Private int ENO;
Private String EName;
Private int Sal;
}
Class worker (wrk)
{
28 bytes
}
Class manager : wrk
{
12 bytes
}
Class A
{ }
Class B: A
{ }
Class A
{
P1 ()
}
Class B:A
{
P2 ()
}
Class A Base class
{
}
Class B: A derived class
{
}
Class C:B derived class
{
}
Class c : A, B
C obj = new c ()
Obj .P1 ()
Not possible (or) supported in .net.
Multiple inheritances is not supported directly in C #.net.
But a similar structure is supported with the help of Inheritance.
It is not supported
It contains multiple Inheritance
B obj = new B()
Private data is accessible only from the class where these are declared.
Protected data is accessible from ALL SUBCLASSES (derived class )also.
Class B : Private A -à C ++ Concept
Public data is accessible in the derived class as well as from objects
Ex 1:-
A company gives Bonus, when they are reaching the target, then calculate the total salary.
ENO
SAL
BONUS
%S (Total Salary)
Open windows forms application project Place a button Code in GD
Class EMP
{
Private int ENO = 101;
Protected int Sal = 5000;
Public void print ()
{
Message. Box. Show (E no + “” + Sal);
}
//print
}
// class (EMP)
Class bonus : EMP
{
Private int b, ts;
Public void calculate (int n)
{
B = n;
Print ();
Ts = Sal +b;
Message Box. Show (“Total” + ts);
}
}
//Bonus Code for
Button1_click
{
Dialog Result dr;
Dr = Message Box . show (“R u getting bonus”, “Peers”, Message Box Buttons. Yes No, Message Box Icon .Question );
If (dr = = Dialog Result .yes)
{
Bonus obj = new bonus ();
Obj. Calculate (3000);
}
Else {
EMP X = new EMP ();
print ();
}
(or) new EMP ().Print (); // name less object
}
Public void Print ()
{
MB.S (“A”)
}
Public void show ()
{
MB.S (“B”);
Print ();
}
B obj = new B ();
Obj. Show () Obj. Print ()
Overriding is a concept of having two methods with the same name and the same arguments in Base and derived classes.
In overriding by default the priority will be given to local class methods.
In overriding, in order to access parent class method s,
the “base” keyword is required. ”base” keyword can be used with methods, fields, and constructors also.
{
MBS (“A”);
}
{
MBS (“B”);
}
base. show ();
{
MBS (“C”);
}
base. Show ();
New c () .show ();
Example on overriding Fields
open window forms application project
place a button
code in GD
Class A
{
Public int x = 10;
}
Class B :A
{
Private int x = 100;
Public void print (int x)
{
Message Box. Show (This. x + “”) ;
//100
Message Box. Show (base. x + “”) ;
//10
Message Box. Show (This. x + “”) ;
//1000
}
}
Code for Button 1_click
{
B obj = new B ();
Obj. print (1000);
Message Box .Show (obj . x + “”);
//10
}
Sealed classes are not inheritable Sealed is a keyword When a class is providing full functionality as per the requirements, then recommended to declare that classes as “sealed class”
Open windows forms application project Place a button Code in GD Sealed
class test
{
Public void divide (Sting s)
{
String [] x = s. split (“”);
For (I =0; I < x. length; I ++)
Message Box. Show (x [i]);
}
// divide
Class abc : test
{
// gives an error
}
Code for Button1 _ click
Private void Button1_click (----)
{
Test t = new test ();
Divide (“this is for test”);
}
Place a breakpoint (Right-click on any line on the source code, select breakpoint, insert breakpoint).
Press F5 for execution.
Click on button 1.
The execution will be stopped at a breakpoint.
To continue line by line execution press F11.
To observe the value of a variable, right-click on a variable name, Add watch.
24:Tf9f,These core tutorials will help you to learn the fundamentals of .NET. For an in-depth understanding and practical experience, explore Online ".NET Training"
int a = 10; b = 20;,c;
C= a + b-30 (Addition)
String S1 = ‘ABC’, S2 = ‘XYZ’,S3;
S3 = S1+S2Abc xyz (concatenation)
Assume that test is a class and t1,t2,t3 are objects then
T3 = t1+t2
gives an error ‘+’ operator is developed to use with numbers and string only BUT NOT WITH OBJECTS.
Operator overloading is a concept of extending the functionality of an Existing operator.
All the operators are overloadable except those contains a.
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That is the following operators are not overloadable.
member Access operator
:: Ternary or conditional operator
:: property access operator
: Inheritance operator
While overloading relational operators, these must be overloaded in ‘PAIR’.
To overload >, < must be overloaded
To overload >=, <= must be overloaded.
To overload ==,!= must be overloaded.
An overloaded operator must be declared as static.
Operator is a keyword.
Syntax to overloaded an operator
Public static return type operator + (args)
{
Logic;
}
Example:- on overloading + operator for adding the objects
Class EMP {
Private int Sal;
.
.
.
.
}
E1
Sal (5000) E2
Sal (8000) E3
Sal (2700)
E1+E2+E3 = EMP(Data type)
Open windows forms Application project à Place a button
Code in GD
Class EMP
{
Private int Sal;
Public EMP (int x )
// constructor
{
Sal = X;
}
Public EMP ()
// Default constructor
{}
Public void Print ()
{
Message Box. Show (Sal);
}
//overloading + public static EMP operator + (EMP X , EMP y)
{
EMP t = new EMP ();
Sal = X. Sal + Y. Sal;
return t;
}
operator overloading
}// EMP class
Code for Button 1_click
{
EMP e1 = new EMP (5000);
EMP e2 = new EMP (8000);
EMP e3 = new EMP (5000);
EMP total = new EMP ();
Total = e1 +e2+e3 ;
Total .Print ();
}
Class Circle { Private int x, y, z; Private Static double pi = 3.14;. } Static is a keyword. Static keyword can be used with fields, constructors, methods, and classes. Static Fields will be created only once while the class is loaded into the memory. Instance Variables will be created separately with every object. Static variables create common memory which is sharable by all the objects. If the Static variable is public, then it can be accessed directly with the class name But NOT WITH OBJECTS.
Observations
Class Test
{
Public int I;
Public Static int S;
}
Test I = 10;
wrong Test s =20;
correct Test t = new Test ()
I = 10; correct
t.s = 20;
wrong
A static constructor can access only static variables.
Static constructor will be executed only once, While class is loading into the memory.
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Example of static variables and static constructor
Open windows form Application Project
Place a button
Code in GD
Class Test
{
Private int I;
Private Static int s;
Static Test ()
// Static constructor
{
S= 0;
}
Public Test ()
//Normal Constructor
{
I = I +1;
S = s+1;
Message Box>show (I + “” +s);
}
}
//Test Code for button 1_ click
{
Test t1 = new Test ();
Test t2 = new Test ();
Test t3 = new Test ();
}
S=0
T1 I =0
I=0 +1
I =1
S=1
I s
1 1
T2 I =0
I = 0+1
I =1
S =s +1
S =I +1
S= 2
I s
I 2 t2
I s
I 3 t3
Class JA (Joint account) {
Private string Name ()
Class Test
{
Public Static void P1 ()
{}
Public Static void P2 ()
{}
}
A static method can access only static data. The static method needs to be called with the class name.
When a class contains all static methods only. Then recommended to declare that class as static. Static class are not intangible (creation of an object is not allowed)
Example of static method and static classes
Open windows Application Project àPlace a text box and a button
In this program, a predefined class called a process is required.
Process class is a part of the System. Diagnostics namespace.
In order to use process classes, this namespace needs to be imported with the help of the “using” keyword.
Code in GD Static classes software { Public static void open (string s) { Process. start (s); }//open }//software class
code for Button 1-cilck { Software. open (text Box1.text); }
A constructor is a special type of method, will be executed automatically while an object is about to create. De Constructors is a special type of method, will be executed automatically while an object is about to destroy. Constructors name must be the same as a class name without “RETURN TYPE”
Syntax
Public CL_Name () { }
De Constructor name must be the same as a class name without a field ( ~) Prefix and without return type and access specifier.
Syntax
CL_ Name () { } Constructors are over loadable.
De -Constructors are not overloadable. Generally, constructors will be used to initialize the fields, to open connections or Files, etc.. Generally, deconstructors will be used to De Allocate the memory and to close the connections and files, etc.
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Open windows form Application Project à Place a button à Code in GD
Class Test
{
Public Test ()
//Constructor
{
Message Box. Show (“From Constructor ”);
}
~ Test ()
// De- Constructor
{
Message Box. Show (“From De -Constructor”)
}
}
/Test
Code for Button 1_click
{
Test t1 = new Test ();
Test t2 = new Test ();
Test t3 = new Test ();
}
Execute the project
Observations
When the above project is executed, then 3 times the constructor and 3 times de-constructor will be executed. After a project is terminated (closed), then within 2 sec Garbage collector will be loaded into the memory. Garbage collector Reclaims (clears), the memory allocated for the current project. The garbage collector can be invoked programmatically also with the help of GC. Collect ()
27:T1003,
Function overloading is a concept of writing more than one function with the same name and with different types of arguments.
Observations
| Proto type | possible to overload |
| Public void Print () | 1 & 2 Not possible |
| Private Void Print () | 1 & 3 Not possible |
| Public int Print () | 1& 4 Yes |
| Public void Print (Int x) | 4 & 5 NO |
| Public void Print (int y) | 4 & 6 Yes |
| Public void Print (ref int x) | 4 & 7 Yes |
| Public Void Print (out int x) | 6 & 7 No |
| Public void Print () | 1 &8 Yes [Not overloading concept] |
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Example on function overloading
Open Window forms Application Project Place a Button Code in GD
Class Test
{
Public void print ( float x)
{
Message. Box. Show (“From float :” + X);
}
Public void Print (double X)
{
Message. Box. Show (“From double:” + X);
}
Public void Print (decimal X)
{
Message. Box. Show (“From decimal:” + X);
}
}
//test Code for button1_click Test t = new Test ();
Print (4.0) ;//
//t. Print (4); error
Print (4f);//float
Print (4m);//decimal
Print (4d);//double
The variable created within the class is called “Instance variables”. The variables created within a function are called “local variables”. When instance variables names and local variable names are the same then by default priority will be given to the local variables In the above case in order to access instance variables this keyword is required. This keyword always points to the currents class. This will be created at run time. Example of “this” keyword with instance and local variables.
Place a button
Code in GD
Code
Class EMP
{
Private int Sal = 5000;
Public void incr (int Sal)
{
This Sal = this. Sal + Sal ;
}
Public void print ()
{
Message Box. Show (“Sal = ” + Sal)
}
Code for Button 1_ click
EMP e1 = new EMP ();
E1.incr (3500); E1.print ();
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Syntax
<Access Specifier>return type func _name (args) C#
.net allows to pass the arguments in three ways:-
Call by value
Call by reference
Call by out
When formal arguments are modified and if modification is reflected on actual arguments, then the concept is called as “call by reference” When formal arguments are modified and if modification are not reflected on actual arguments, then the concept is called as “call by value” By default variables will be passed by value. Reference is a keyword which is required to pass a variable The variables which are passing by ref must be initialized Reference keyword must be used along with actual and formal arguments.
Example on call by value and call by reference
Open windows form application project
Place a button
Code in GD
Class Test
Public void SWAP (int a, ref int b)
{
Int t = a;
A= b;
B =t;
}
}
Code for Button 1 _click
Private void button1_click ()
{
Int x = 10;
y = 20;
Test t = new Test ();
t.SWAP (x, ref y);
Message Box. Show (x + “” + y);
}
It is 99% similar to cal by ref. Out is a keyword Out allows to pass a variable without initialization also. Event if out variable is initialized, the value will not be passed. out = ref _ initialization
Example on call by out
Place a button Code in GD
Class test
{
Public void print (out int x)
{ X =10;
X= x +x;
}
}
Code for button 1_ click ()
Private void button1_ click ()
{
Int a ;
Test t = new Test ();
t.Print (out a);
Message Box. Show (a);
}
Arrays are of type “reference” That is even if an Array is not initialized still it holds some default values.
int a, b, c ; C = a + b; STACK
Array X(5) x=5000 HEAP
The array is a collection of homogeneous data type Arrays shares the same name with different index values Always index starts from ‘0’ Arrays will be stored in continuous memory Arrays are faster in accessing All the arrays are instance of the system. Array class
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↓
C# supports three types of Arrays One-dimensional arrays Multidimensional arrays Jagged Arrays
Syntax Data type [] arr_name = new data type [size];
Example 
While initializing an array, size is not recommended
Example
A program to print array default rules:-
Open window forms application project Place a button Code for button 1
click
{
Int [] x = new int [2];
For (int I =0 ; i< arg.length ; I ++);
Message Box. Show ( x [i]+ “”);
}
Output
Observations
The integral Array default value is Zero. Floating Array default value is Zero.
char Array default value is nothing. Bool Array default value is false.
Date time Array default value is 1/1/0001 12:00:00 AM.
A program to create or get the spelling of a given number (1…………………..999) 123…………..one hundred twenty-three Open windows forms application project Place two text boxes and a button 
Code for button1
click
{
Int n = int. parse (text box 1.text);
Int I = 0;
String res = “”;
String [] ones = new string []
{ “one”, “two”, “three”, “four” “five”, “six” ………………,” nineteen”};
String [] Tens = new string []
{“ten”, “twenty”, “ninety”};
N = 426 N = 426/ 100 -à 10/3 = 3
If (n > 99 && n < 1000)
{
I = n / 100; Res = ones [I - 1] + “hundred”; N = n % 100;
}
If (n > 19 && n < 1000)
{
I = n / 100; Res = ones [I - 1] + “hundred”;
N = n % 100;
}
If (n > 0&& n < 20)
Res =res + ones [I - 1] ;
Text Box 2.text = res;
F5
}
Arranging a set of elements in rows and columns is called “Multi-Dimensional Array”.
In a Multi-Dimensional Array, every row must contain the same number of elements. Multi-Dimensional Array size will be represented with no. of rows X no. of columns If the array name is ‘X’ then x. length return a total number of elements.
get length (0) returns no. of rows get length (1) returns no. of columns syntax to declare multi – d array I0 : int [] x = new int [s]; S 20 : int [,] x = new int [s,s]; 30 : int [,,] x = new int [s,s,s];
Note VB supports up to 32 dimensions where as no limit in C #.NET Syntax to initialize 2 D Array Int [,] x = new int [,] { {5,6,7,8} {9,8,7,6} {5,5,5,5} }
Example with multi dimension Array
Open windows forms application project Place a button Code for button 1
click
{
String s = “”;
Int [,] x = new int [,];
{ {5, 6, 7, 8}, {9, 8, 7, 6}, {5, 5, 5, 5} };
r=0 c = 0 Rr=1 c =1 c =2 c =3 message box. Show (“Total :” + x. length) ;
message box .show (“Rows : + x. get length (0)”) + “ cols :” + x. get length (1) );
For (int r = 0; r < x. get length (0);r ++)
{
For (int c = 0; c< x. get length (0);c ++)
{
S = S + X [r,c] + “” ;
}
S= s + “/n”
}
Message Box. Show (s);
ABC(Company) Members are working Employees 3*6values
A jagged array is a collection of rows where every row may contain a different number of elements. Jagged arrays save memory. Jagged arrays are faster in accessing. Jagged arrays are also called as “Dynamic array” (run time array) Jagged array is also called an array of arrays.
Syntax Int [] [] x = new int [3] []; X [0] = new int [] {4,2,3,5,6,7} X [1] = new int [] {3,8,4,2,4}
Example Open windows forms application project Place a button Code for button 1
click
{
Int [] [] x = new int [3][];
X [0] = new int [] {5,3,4,6,7,7};
X [1] = new int [10];
X [2] = new int []{2,3};
String S = “”;
For (int r = 0;r < x.get length (0);r ++)
{
For (int c = 0;r < x.get length (0);c++)
{
S= s + x[ r][c] +””;
}
S =s + “/n”
}
Message Box. Show (s);
For (initialization ; condition , ++ (or) --)
{
Statements;
}
While (condition)
{
Statements ;
}
Do
{
Statements ;
}
While (condition)
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Example on for loop
Place a button on the form then Add 10 text boxes in to the form when clicked on a button
Open windows forms application project Place a button Code for button 1
click
{
Int X = 30;
For (int I =1; i<10; I++);
{
Text box t = new text box ();
location = new point (100,x);
this. Controls .Add (t);
x = x + 30;
}
Press f5
Execute the project
Observations
In C # .net all the controls are predefined classes.
2b:T22fb,
Data type Type of data Data type specifies the size of the data and type of data. C#.net data type is divided into two types
Value Type Int i = 0 I 10 (7000) C language C#
Reference Type Int * p = i p 7000 (9000) Stack Heap 90% 10% 10% 90%
The value type will be created at compile-time and these will be started in STACK memory. Value types hold the data directly No default value for value type GC (Garbage collector) cannot access stack memory. that is GC can not clear stack run time Examples
Pre-defined data types
Structures
Enum’s (Enumerator)
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Reference Type will be created at run time and these will be stored in HEAP memory. Reference Type holds the reference but not the data. The reference Type holds the default value. GC can access HEAP memory. Examples:-
Classes
Object
Arrays
Interface
Delegates
Var (newly introduced)
Etc……………
These are divided into 4 groups
Group 1:- Integral Data type
.byte 1 byte 0 255
.S byte 1 byte -128 to +127
.Short 2 bytes -32768 to +32768
.U short 2 bytes 0 – 65535
Int 4 bytes ~ +- 214 cores
U int 4bytes 0 -~ 429 cores
Long 8 bytes + 2^63
U Long 8 bytes 0 – 2 ^ 64 -1
Group 2:- Floating Related Data Types
*float 4 B
*double 8 B
*decimal 16 B
Group 3:- character Related Data types
.char 2 B: char holds UNICODE (universal coding) characters that are required for globalization.
.String 16 B : 4 GB
Group 4 :- other Data type
.bool 1 B true/ false
.Data time 12 B
1/1/0001 to 31/12/9999
Syntax to declare a variable
<Data type> var name = value;
Note:- In C# .net always variable name need to be started either with alphabet, underscore, @ symbol
Obs :-
Int a =90;
Int – a = 90;
Int @a = 90;
Int *a = 90;
Int 2a = 90;
Int if = 90;
Example on Data Types
Open console Application project.
Write the following code in the main method.
Int I = 90;
Console. Write Line (i);
Float x = 4.0 f Console. Write Line (x);
Byte b1 = 10, b2 = 20;
Int c = b1 + b2;
Console. Write Line (c);
Console. Write Line ();
Execute the project :(f5)Observations
value types must be initialized before using
float X = 4.0 gives an error
Reason
By default 4.0 will be treated as double;
Solution: -
float x = 4. 0 F (or) float X = 4. 0f;
A number, which is post fixed with f @ F is called as float.
A number, which is post fixed with d @ D is called as double.
A number, which is postfixed with m@ M is called decimal.
Byte c = b1 + b2, gives an error + operator returns the result in the format of int.
2c:T1b3c,Go to visual studio.net
Click on file
Click on new
Click on project
Select visual c# from the installed template.
Select ASP.net WVC web application template
Type the application name (example)
Select the location to save
Click on ok.
This will create an ASP.net MVC2 web application.
When we create ASP.net MVC2 web application it will create 5 folders.
Content folder:
This folder will contain all the required CSS files that is to be attached to the view pages.
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Views folder:
By default, the views folder will contain 3 folders as follows
Then every folder contains some view page.
The shared folder contains commonly used files like master pages, user control, etc.
Here we find only .aspx pages we do not find .cs files
.cs files will be available in the controller’s folders and models folder.
Controllers folder:
This folder will contain one .cs file for every folder available in views.
In view, we have a home folder and account folder so we find two supported files in controller folders.
Every controller file will contain some method called action method with the name of the webpage.
I.e. home controller.cs we find 4 action methods
Change password ()
Change password success ()
Logon ()
Register ()
Models folder:
This folder will contain one super file one each folder available in views
In case the view contains the data from the database
Scripts folder:
It will contain all javascript and journey files that contain the code related to validation.
2d:T7d05,
Welcome to .NET Tutorials. The objective of these tutorials is to get an in-depth understanding of .NET. The tutorial starts with an overview of .NET.
In addition to these tutorials, we will also cover common issues, Interview questions, and How To’s of MongoDB.
.NET is both a business strategy from Microsoft and its collection of programming support for what are known as Web services, the ability to use the Web rather than your own computer for various services. Microsoft's goal is to provide individual and business users with a seamlessly interoperable and Web-enabled interface for applications and computing devices and to make computing activities increasingly Web browser-oriented. The .NET platform includes servers; building-block services, such as Web-based data storage; and device software. It also includes Passport, Microsoft's fill-in-the-form-only-once identity verification service.
These core tutorials will help you to learn the fundamentals of .NET. For an in-depth understanding and practical experience, explore Online ".NET Training"
The Microsoft .NET initiative is a very wide initiative and it spans multiple Microsoft Products ranging from the Windows OS to the Developer Tools to the Enterprise Servers. The definition of .NET differs from context to context, and it becomes very difficult for you to interpret the .NET strategy. This section aims at demystifying the various terminologies behind .NET from a developer’s perspective. It will also highlight the need for using this new .NET Platform in your applications and how .NET improves over its previous technologies.
Windows DNA is a concept for building distributed applications using the Microsoft Windows operating system and related software products.
First, we will understand the 2- tier, 3- tier, and then move on to N- tier Windows DNA.
Through the appearance of Local-Area-Networks, PCs came out of their isolation, and were soon not only being connected mutually but also to servers. Client/Server- computing was born. A two-tiered application is an application whose functionality can only be segmented into two logical tiers, presentation services, and data services. The presentation services of a two-tiered application are responsible for gathering information from the user, interacting with the data services to perform the application's business operations, and presenting the results of those operations to the user. The Presentation services are also called the presentation layer because it presents information to the user. Things you might find in a presentation layer include a Web browser, a terminal, a custom-designed GUI, or even a character-based user interface. The client-Server architecture was a major buzzword in the early '90s, taking initially dumb terminal applications and giving them a fancy windows-like front end, using PCs with terminal emulators which presented pretty GUIs (Graphical user interface) or later Visual Basic, etc front-ends. A web browser talking to a web server is an example of a client talking to a server. Here there is presentation logic (presentation tier) happening at the client, and data/file access (data access tier) and logic happening at the server. One reason why the the2-tier model is so widespread is because of the quality of the tools and middleware that has been most commonly used since the ’90s: Remote-SQL, ODBC, relatively inexpensive, and well-integrated PC-tools (like Visual Basic, Power-Builder, MS Access,4-GL-Tools by the DBMS manufactures). In comparison, the server-side uses relatively expensive tools. In addition, the PC-based tools show good Rapid-Application-Development (RAD) qualities i.e. simpler applications can be produced in a comparatively short time. The 2-tier model is the logical consequence of RAD-tools popularity.
Tier: Client Server
In a three-tiered application, the presentation services are responsible for gathering information from the user, sending the user information to the business services for processing, receiving the results of the business services processing, and presenting those results to the user. The most popular architecture on the web currently, mostly taking the form of web browser processing client side presentation in the form of HTML/DHTML, etc, the webserver using some scripting language (ASP) and the database server (SQL Server for example) serving up the data.
The basic functionalities of 3 – Tier or N-Tier follows are
The presentation services tier is responsible for:
-Gathering information from the user
-Sending the user information to the business services for processing
-Receiving the results of the business services processing
-Presenting those results to the user
The business services tier is responsible for:
-Receiving input from the presentation tier.
-Interacting with data services to perform business operations.
-Sending the processed results to the presentation tier.
The data services tier is responsible for the:
-Storage of data.
-Retrieval of data.
-Maintenance of data.
-Integrity of data.
In Windows DNA applications commonly implement their business logic using one or more of three implementation options.
-Asp Pages
-COM components
-Stored procedures running in the DBMS
Writing much business logic in ASP pages is a bad idea. Since simple languages are used, such as Microsoft Visual Basic Script, and the code is interpreted each time it is executed, which hurts the performance. Code in ASP pages is also hard to maintain, largely because business logic is commonly intermixed with presentation code that creates the user interface.
One recommended approach for writing middle-tier business logic is to implement that logic as COM objects. This approach is a bit more complex than writing a pure ASP application. Wrapping business logic in COM objects also cleanly separates this code from the presentation code contained in ASP pages, making the application easier to maintain.
The Third option for writing business logic is to create some of that code as stored procedures running in the database management system (DBMS). Although a primary reason for using stored procedures is to isolate the details of database schema from business logic to simplify code management and security, having code in such close proximity to data can also help optimize performance.
DLL Hell
DLLs gave developers the ability to create function libraries and programs that could be shared with more than one application. Windows itself was based on DLLs. While the advantages of shared code modules expanded developer opportunities, it also introduced the problem of updates, revisions, and usage. If one program relied on a specific version of a DLL, and another program upgraded that same DLL, the first program quite often stopped working.
Microsoft added to the problem with upgrades of some system DLLs, like comctl.dll, the library used to get file, font, color and printing dialog boxes. If things weren't bad enough with version clashes, if you wanted to uninstall an application, you could easily delete a DLL that was still being used by another program.
Recognizing the problem, Microsoft incorporated the ability to track usage of DLLs with the Registry starting formally with Windows 95, and allowed only one version of a DLL to run in memory at a time. Adding yet another complication, when a new application was installed that used an existing DLL, it would increment a usage counter. On uninstall, the counter would be decremented and if no application was using the DLL, it could be deleted.
That was, in theory. Over the history of Windows, the method of tracking of DLL usage was changed by Microsoft several times, as well as the problem of rogue installations that didn't play by the rules--the result was called "DLL HELL", and the user was the victim.
Solving DLL hell is one thing that the .NET Framework and the CLR targeted. Under the .NET Framework, you can now have multiple versions of a DLL running concurrently. This allows developers to ship a version that works with their program and not worry about stepping on another program. The way .NET does this is to discontinue using the registry to tie DLLs to applications and by introducing the concept of an assembly.
On the .NET Platform, if you want to install an application in the client's place all you have to do is use XCopy which copies all the necessary program files to a directory on the client’s computer. And while uninstalling all you have to do is just delete the directory containing the application and your application is uninstalled.
An Assembly is a logical DLL and consists of one or more scripts, DLLs, or executables, and a manifest (a collection of metadata in XML format describing how assembly elements relate). Metadata stored within the Assembly is Microsoft's solution to the registry problem. On the .NET Platform programs are compiled into
.NET PE (Portable Executable) files. The header section of every .NET PE file contains a special new section for Metadata (This means Metadata for every PE file is contained within the PE file itself thus abolishing the need for any separate registry entries). Metadata is nothing but a description of every namespace, class, method, property, etc. contained within the PE file. Through Metadata you can discover all the classes and their members contained within the PE file.
Metadata describes every type and member defined in your code in a Multilanguage form. Metadata stores the following information:
Description of the assembly
-Identity (name, version, culture, public key).o The types that are exported.
-Other assemblies that this assembly depends on.
-Security permissions needed to run
Description of types
Name, visibility, base class, and interfaces implemented.
Members (methods, fields, properties, events, nested types)
•Attributes
Additional descriptive elements that modify types and members
Advantages of Metadata:
Now let us see the advantages of Metadata:
Self-describing files:
CLR modules and assemblies are self-describing. The module's metadata contains everything needed to interact with another module. Metadata automatically provides the functionality of Interface Definition Language (IDL) in COM, allowing you to use one file for both definition and implementation. Runtime modules and assemblies do not even require registration with the operating system. As a result, the descriptions used by the runtime always reflect the actual code in your compiled file, which increases application reliability.
Language Interoperability and easier component-based design:
Metadata provides all the information required about compiled code for you to inherit a class from a PE file written in a different language. You can create an instance of any class written in any managed language (any language that targets the Common Language Runtime) without worrying about explicit marshaling or using custom interoperability code.
Attributes:
The .NET Framework allows you to declare specific kinds of metadata, called attributes, in your compiled file. Attributes can be found throughout the .NET Framework and are used to control in more detail how your program behaves at run time. Additionally, you can emit your own custom metadata into .NET Framework files through user-defined custom attributes.
Assembly
Assemblies are the building blocks of .NET Framework applications; they form the fundamental unit of deployment, version control, reuse, activation scoping, and security permissions. An assembly is a collection of types and resources that are built to work together and form a logical unit of functionality. An assembly provides the common language runtime with the information it needs to be aware of type implementations. To the runtime, a type does not exist outside the context of an assembly.
An assembly does the following functions:
-It contains the code that the runtime executes.
-It forms a security boundary. An assembly is a unit at which permissions are requested and granted.
-It forms a type boundary. Every type’s identity includes the name of the assembly at which it resides.
-It forms a reference scope boundary. The assembly manifest contains assembly metadata that is used for resolving types and satisfying resource requests. It specifies the types and resources that are exposed outside the assembly.
-It forms a version boundary. The assembly is the smallest versionable unit in the common language runtime; all types and resources in the same assembly are versioned as a unit.
-It forms a deployment unit. When an application starts, only the assemblies the application initially calls must be present. Other assemblies, such as localization resources or assemblies containing utility classes, can be retrieved on demand. This allows applications to be kept simple and thin when first downloaded.
-It is a unit where side-by-side execution is supported.
Contents of an Assembly
-Assembly Manifest
-Assembly Name
-Version Information
-Types
-Locale
-Cryptographic Hash
-Security Permissions
Assembly Manifest
Every assembly, whether static or dynamic, contains a collection of data that describes how the elements in the assembly relate to each other. The assembly manifest contains this assembly metadata. An assembly manifest contains the following details:
Identity. An assembly's identity consists of three parts: a name, a version number, and an optional culture.
File list. A manifest includes a list of all files that make up the assembly.
Referenced assemblies. Dependencies between assemblies are stored in the calling assembly's manifest. The dependency information includes a version number, which is used at run time to ensure that the correct version of the dependency is loaded.
Exported types and resources. The visibility options available to types and resources include "visible only within my assembly" and "visible to callers outside my assembly."
Permission requests. The permission requests for an assembly are grouped into three sets: 1) those required for the assembly to run, 2) those that are desired but the assembly will still have some functionality even if they aren't granted, and 3) those that the author never wants the assembly to be granted.
In general, if you have an application comprising of an assembly named Assem.exe and a module named Mod.dll. Then the assembly manifest stored within the PE Assem.exe will not only contain metadata about the classes, methods, etc. contained within the Assem.exe file but it will also contain references to the classes, methods etc, exported in the Mod.dll file. While the module Mod.dll will only contain metadata describing itself.
The following diagram shows the different ways the manifest can be stored:
For an assembly with one associated file, the manifest is incorporated into the PE file to form a single-file assembly. You can create a multifile assembly with a standalone manifest file or with the manifest incorporated into one of the PE files in the assembly.
The Assembly Manifest performs the following functions:
-Enumerates the files that make up the assembly.
-Governs how references to the assembly's types and resources map to the files that contain their declarations and implementations.
-Enumerates other assemblies on which the assembly depends.
-Provides a level of indirection between consumers of the assembly and the assembly's implementation details.
-Renders the assembly self-describing.
Modules are also PE files (always with the extension .netmodule) which contain Metadata but they do not contain the assembly manifest. And hence in order to use a module, you have to create a PE file with the necessary assembly manifest.
In C#, you can create a module using the /t:module compiler switch.
There are a few ways to incorporate a module into an Assembly. You can either use /addmodule switch to add module/s to your assembly, or you can directly use the /t:exe, /t:winexe and /t:library switches to convert the module into an assembly.
Difference between Module and Assembly
A module is an .exe or .dll file. An assembly is a set of one or more modules that together make up an application. If the application is fully contained in a .exe file,fine—that's a one-module assembly. If the .exe is always deployed with two .dll files and one thinks of all three files as comprising an inseparable unit, then the three modules together form an assembly, but none of them does so by itself. If the product is a class library that exists in a .dll file, then that single .dll file is an assembly. To put it in Microsoft's terms, the assembly is the unit of deployment in
.NET.
An assembly is more than just an abstract way to think about sets of modules. When an assembly is deployed, one (and only one) of the modules in the assembly must contain the assembly manifest, which contains information about the assembly as a whole, including the list of modules contained in the assembly, the version of the assembly, its culture, etc.
When compiling to managed code, the compiler translates your source code into Microsoft intermediate language (MSIL), which is a CPU-independent set of instructions that can be efficiently converted to native code. MSIL includes instructions for loading, storing, initializing, and calling methods on objects, as well as for instructions for arithmetic and logical operations, control flow, direct memory access, exception handling, and other operations. Before code can be executed, MSIL must be converted to CPU-specific code by a just-in-time (JIT) compiler. Because the runtime supplies one or more JIT compilers, for each computer architecture it supports, the same set of MSIL can be JIT-compiled and executed on any supported architecture.
When a compiler produces MSIL, it also produces metadata. The MSIL and metadata are contained in a portable executable (PE file) that is based on and extends the published Microsoft PE and Common Object File Format (COFF) used historically for executable content. This file format, which accommodates MSIL or native code as well as metadata, enables the operating system to recognize common language runtime images. The presence of metadata in the file along with the MSIL enables your code to describe itself, which means that there is no need for type libraries or Interface Definition Language (IDL). The runtime locates and extracts the metadata from the file as needed during execution.
Debugging is the most important feature of any programming language and Visual Studio
.NET IDE provides this feature in an effective manner (but you can still do a pretty good job with the .NET SDK alone). The application source code goes through two distinct steps before a user can run it. First, the source code is compiled to Microsoft Intermediate Language (MSIL) code using a .NET compiler. Then, at runtime, the MSIL code is compiled to native code. When we debug a .NET application, this process works in reverse. The debugger first maps the native code to the MSIL code. The MSIL code is then mapped back to the source code using the programmer's database (PDB) file. In order to debug an application, these two mappings must be available to the .NET runtime environment.
To accomplish the mapping between the source code and the MSIL, use the/debug:pdbonly compiler switch to create the PDB file (Note: When building ASP.NET applications, specify the compilation setting debug="true" in the application’s Web.config file). The second mapping between the MSIL code and native code is accomplished by setting the JITTracking attribute in our assembly. By specifying the /debug compiler switch, the PDB file is created and the JITTracking attribute is enabled. When using this compiler switch, a debugger can be attached to an application loaded outside of the debugger.
Once the required mappings exist, there are several means by which to debug our applications. We can use the integrated debugger within Visual Studio .NET, or, if we prefer, we can use DbgClr, a GUI-based debugger. There is also a command-line debugger, CorDBG that is included in the .NET Framework SDK.
-Newest technology from MS for app development
-Supports fully managed, but also a hybrid mix of managed and native through P/Invoke and Managed/Unmanaged C++, which means that its easier to write code that doesn't have lots of memory leaks
-WPF and WCF are the new way of building UI's and Communicating between processes and systems
-Fully integrated IDE available
-Linux and Mac support through 3rd parties (Mono)
-Many languages available, both dynamic (IronPython and IronRuby) and static (C#, VB.NET, C++), both object-oriented (C#, VB.NET, C++) and functional (F#)
- Multi-platform support isn't available from MS and isn't available straight after installing Visual Studio - Managed code can be slower than native code
Application domains offer all the benefits of process isolation but are much more efficient than processes. The Microsoft .NET runtime host automatically manages the loading/unloading of the assemblies into the appropriate application domains. However, Microsoft .NET Framework class library also offers application developers with various classes that can be used to programmatically create application domains and ensure that the various applications can be isolated from each other. Also, inter-application communication is not that expensive because context switching is not involved in application communication using application domains in Microsoft .NET.