Asp.net with c# Help, Javascript, sql query, c#.net question

Get FckEditor value using javascrip

2011-04-14T05:45:00.000-07:00

How can I get the value of fckeditor using javascript or jquer.
>> var inst = FCKeditorAPI.GetInstance("description");
var html = inst.GetHTML();

where description is the name or id of fckeditor instansce

Find row index of gridview on RowCommand without CommandArgument

2010-02-03T03:45:00.000-08:00

Gridview has a template field with item linkbutton delete with CommandName now when user click on linkbutton then find the rowindex on Rowcommand event of gridview using C#.net

protected void grdtest1_RowCommand(object sender, GridViewCommandEventArgs e)
{
if (e.CommandName == "DeleteRow")
{
LinkButton gv = (LinkButton)e.CommandSource;
GridViewRow gvr = (GridViewRow)gv.Parent.Parent;
int rownum = gvr.RowIndex;
}
}

Bind multiple column value in row in gridview using asp.net(c#.net)

2009-04-03T04:24:00.000-07:00

Problem: I want to bind more than one column value in row in gridview . I fetch the value from database in table format now I want to bind the five row value in a single row in grid like this....

<asp:gridview id="'grdpicture'" runat="'server'" autogeneratecolumns="'false'" allowpaging="'true'" borderwidth="'0'" borderstyle="'None'" pagesize="'3'" ondatabound="'grdpicture_DataBound1'"> <columns> <asp:templatefield> <itemtemplate> <ul class="'thumb'"> <%#DataBinder.Eval(Container.DataItem,'photo1')%> <%#DataBinder.Eval(Container.DataItem,'photo2')%> <%#DataBinder.Eval(Container.DataItem,'photo3')%> <%#DataBinder.Eval(Container.DataItem,'photo4')%> <%#DataBinder.Eval(Container.DataItem,'photo5')%> </ul> </itemtemplate> </asp:TemplateField> </columns> </asp:GridView"> *******This is the c# code to bind gridview using System; using System.Data; using System.Configuration; using System.Collections; using System.Web; using System.Web.Security; using System.Web.UI; using System.Web.UI.WebControls; using System.Web.UI.WebControls.WebParts; using System.Web.UI.HtmlControls; protected void Page_Load(object sender, EventArgs e) { if (!IsPostBack) { showimage(); } } protected void showimage() { { string select = "select photoname,phototitle,photoname_big from stone_tbl "; Dt = Str_con.ExecuteQuery(select); DataTable fivepict = new DataTable(); fivepict.Columns.Add("photo1", typeof(string)); fivepict.Columns.Add("photo2", typeof(string)); fivepict.Columns.Add("photo3", typeof(string)); fivepict.Columns.Add("photo4", typeof(string)); fivepict.Columns.Add("photo5", typeof(string)); if (Dt.Rows.Count > 0) { int i = 0; bool save = true; while (i < dr =" fivepict.NewRow();" j =" 1;" col = "photo"></li>"; i++; if (i == Dt.Rows.Count) { fivepict.Rows.Add(dr); save = false; j = 6; } } if (save) fivepict.Rows.Add(dr); } grdpicture.DataSource = fivepict; grdpicture.DataBind(); } else { grdpicture.DataSource = Dt; grdpicture.DataBind(); } } catch (Exception ex) { } }

Replace enter key value from textbox using asp.net with c#.net and save in database

2009-03-24T03:10:00.000-07:00

Problem: when I wants save multiline textbox value in database using asp.net with c#.net and show as it is its not happening ....
Actually the problem is when we enter the value in textbox and press enter key. value like this
this is dilip
web developer
it save in database but when fetch value from database its showing in same line like this: this is dilip web developer

solution: string txtvalue = mytextbox.Text.ToString().Replace("\r\n", "
");
and save it.
Because enter key value is \r\n . and now it will show as u entered text

Return last date of the current month using sql

2009-03-18T02:15:00.000-07:00

SELECT datepart(dd,DateAdd(day, -1, DateAdd(month, DateDiff(month, 0, getdate())+1, 0))) AS Dateval

How get month name,weekday name,year using sql

2009-03-17T23:32:00.000-07:00

RETURN THE WEEKDAYNUMBER
select datepart(dw,getdate()) as weekdaynumber
RETURN THE WEEKDAYNAME
select datename(dw,getdate()) as weekdayname
RETURN THE CURRENTDATENUMBER
select day(getdate()) as currentdatenumber
RETURN THE CURRENTDATE
select GETDATE() as currentdate
RETURN THE CURRENTYEAR
select year(getdate()) as currentyear
RETURN THE CURRENTMONTHNUMBER
select month(getdate()) as currenmonthnumber
RETURN THE CURRENTDATENUMBER
select day(getdate()) as currentddatenumber
RETURN THE MONTHNAME
select datename(mm,getdate()) as currentmonthname

Get 2nd(second) lowest sallery using sql

2009-03-17T23:10:00.000-07:00

select top 1 * from (select top 2 * from sallery_tbl order by usallery asc) as Sallery order by USallery desc

where Sallery_tbl is table name and usallery is column name

Update Table value with case in Sql

2009-01-11T23:59:00.000-08:00

Use case for update the table value using sql query
Ex. table Gender_tbl and like this
id Gen_Name
1 Male
2 Male
3 Female
4 Femal
5 Male
no I have to update Gen_Name Male with M and Femal with F
solution:
UPDATE GENDER_TBL SET Gen_Name= (CASE WHEN (Gen_Name='Male') THEN 'M' WHEN (Gen_Name='Female') THEN 'F' else ' ' end)

Posted by Dilip Kumar

Return Multiple Column vaue in Single column with comma separated using Sql

2009-01-11T22:27:00.000-08:00

How can get multiple coumn value in single column with camman separeted using sql. like
I have table test2 and column name id and value like this
Id
1
2
3
4
5
6
..
and I want result like this 1,2,3,4,5,6,....
solution:
declare @a varchar(500)
set @a = ' '
select @a = @a + cast(id as varchar(20)) + ',' from test2
if len(@a)>1
set @a= left(@a,len(@a)-1)
select case @a when ' ' then '0' else @a end as id

Spacebar Check in TextBox Using Javascript

2009-01-11T22:08:00.000-08:00

Trim Function using java script.Validation for text box if there only space using java script.validation for space in text box using java script.

Solution:

Create A textbox with id txtname and a button id btntest and wite this function inside script tag.

function trim(string)
{
var a = string.replace(/^\s+/, '');
return a.replace(/\s+$/, '')
}
function TestTrim()
{

x = window.document.getElementById("txtname");
str="Please Enter User Name";
if (trim(x.value)=="")
{
alert(str);
x.select();
x.focus();
return false ;
}
}

And then call the function on c#(code behind page)
btntest.Attributes.Add("onclick", "return TestTrim();");

How can search column in database using sql

2009-01-07T03:35:00.000-08:00

How can search column in database using sql.

solution:-
use databasename
select it and execute and then write this query and execute it . it will give all the table in wich there will be the column name like you search.
select * from information_schema.columns where column_name like '%abc%'

Search the table from database using sql

2009-01-07T03:28:00.000-08:00

How can search the table name from the existing database if there are table exist but I forgot the full name of table in sql

Solution:- select * from information_schema.tables where table_name like '%abc%'

where abc is table name

Convert Asp.net to Asp.net Ajax enabled website in Asp.net 2.0

2008-10-16T03:30:00.000-07:00

How can I convert the asp.net website to Ajax enabled website in asp.net 2.0

This quation was very difficult for me change the simple website to Ajax enable website. Simply if we want to make ajax enabled website then select the Ajaxenabledwebsite from the Dashboard when click on file new and website. but if I din't this then I faced problem to convert this asp.net website to Ajax enabled website. its very simple

step1: add the ajaxcontrolltoolkit.dll in your application bin folder by add refrence.

step2: add the some line of code in web.config inside the

<httphandlers><br />   <remove verb="*" path="*.asmx"><br />   <add verb="*" path="*.asmx" validate="false" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"><br />   <add verb="*" path="*_AppService.axd" validate="false" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"><br />   <add verb="GET,HEAD" path="ScriptResource.axd" type="System.Web.Handlers.ScriptResourceHandler, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" validate="false"><br />  </httphandlers><br />

Disable or readonly the checkbox using javascipt

2008-09-19T06:40:00.002-07:00

For disable or readonly the checkbox using javascipt use the disable property of checkbox.

document.getElementById("ChkBoxName").disabled =false;

And for the Enable the checkbox using javascript

document.getElementById("ChkBoxName").disabled =true;

Check the column value if value is in string format with coma separated using Sql

2008-09-19T06:40:00.001-07:00

If column value is in 1,2,34,23,44,444,12,23,... format than how can check the value using like operator in Sql. means if the coma separated value is in column in any table then how can check the value using like operator in Sql.

solution:
select * from s
where
sid like '44,%' or sid like '%,44,%'
or sid like '%,44' or sid='44'

where sid is column name
this will only return the 44

Return Multi Row value in a single column with comma seprated

2008-09-19T06:40:00.000-07:00

Return Multi Row value in a single column with comma seprated using sql
I want Return output like 1,2,3,4,5 using sql.
There is one table in which has column
id name
1 Dilip
2 Dinesh
3 Varun
4 Dhanpat
5 Renuka

solution:
declare @a varchar(500)
set @a = ' '
select @a = @a + cast(id as varchar(20)) + ',' from tablename
if len(@a)>1
set @a= left(@a,len(@a)-1)
select case @a when '' then '0' else @a end as id

Use case , becaue may be there is no any value in this table so it will retun o

Factory patteren based code in C#.net

2008-07-27T21:29:00.000-07:00

IMPLEMETN THE INTERFACES AND USE IT FACTORY PATTERN BASE CODE

using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;

public interface myinterface
{
int add(int x,int y);
//int mul(int w, int z);

}

public class class1 : myinterface
{
public int add(int a, int b)
{
int c = a + b;
return c;
}

}

public class class2 : myinterface
{
public int add(int j, int k)
{
int l = j * k;
return l;
}

}

class Factory
{
public myinterface GetObject(int type)
{
myinterface base1 = null;
switch (type)
{
case 1:
base1 = new class1();
break;
case 2:
base1 = new class2();
break;
}
return base1;
}
}

public partial class _Default : System.Web.UI.Page
{
Factory factory = new Factory();
protected void Page_Load(object sender, EventArgs e)
{

}
protected void Button1_Click(object sender, EventArgs e)
{
myinterface mytest = factory.GetObject(1);
int result = mytest.add(Convert.ToInt32(TextBox1.Text.ToString()), Convert.ToInt32(TextBox2.Text.ToString()));
txtresult.Text = Convert.ToString(result);

}

protected void Button2_Click(object sender, EventArgs e)
{

myinterface multiply = factory.GetObject(2);
int multiplevalue = multiply.add(Convert.ToInt32(TextBox1.Text.ToString()), Convert.ToInt32(TextBox2.Text.ToString()));
txtmultiply.Text = Convert.ToString(multiplevalue);

}

}

Regular Expression in dotnet

2008-07-24T05:14:00.000-07:00

Regular expression examples for decimals input

Positive Integers — ^\d+$
Negative Integers — ^-\d+$
Integer — ^-{0,1}\d+$
Positive Number — ^\d*\.{0,1}\d+$
Negative Number — ^-\d*\.{0,1}\d+$
Positive Number or Negative Number - ^-{0,1}\d*\.{0,1}\d+$
Phone number — ^\+?[\d\s]{3,}$
Phone with code — ^\+?[\d\s]+\(?[\d\s]{10,}$
Year 1900-2099 — ^(19|20)[\d]{2,2}$
Date (dd mm yyyy, d/m/yyyy, etc.) — ^([1-9]|0[1-9]|[12][1-9]|3[01])\D([1-9]|0[1-9]|1[012])\D(19[0-9][0-9]|20[0-9][0-9])$
IP v4 — ^(\d|[1-9]\d|1\d\d|2[0-4]\d|25[0-5])\.(\d|[1-9]\d|1\d\d|2[0-4]\d|25[0-5]){3}$

Regular expression examples for Alphabetic input

Personal Name — ^[\w\.\’]{2,}([\s][\w\.\’]{2,})+$
Username — ^[\w\d\_\.]{4,}$
Password at least 6 symbols — ^.{6,}$
Password or empty input — ^.{6,}$|^$
email — ^[\_]*([a-z0-9]+(\.|\_*)?)+@([a-z][a-z0-9\-]+(\.|\-*\.))+[a-z]{2,6}$
domain — ^([a-z][a-z0-9\-]+(\.|\-*\.))+[a-z]{2,6}$

Url — http://([\w-]+\.)+[\w-]+(/[\w- ./?%&=]*)?

Other regular expressions

Match no input — ^$
Match blank input — ^\s[\t]*$
Match New line — [\r\n]|$

How use trigger in sql

2008-07-18T02:07:00.000-07:00

Example of Delete trigger

CREATE trigger [TRIGGER_Deletesubcategory] ON dbo.category

FOR delete

AS

declare @nmid int

select @nmid=sno from deleted

delete from subcategory where cat_id= @nmid

There will be two table one is category and second one is subcategory and the primery key of category table will be sno and the this will foreign key(cat_id) for subcategory table.

Image Thumbnail using C#.net

2008-07-11T22:28:00.000-07:00

//This is resize function to set image size as you want
resizeimage(imagename); (where imagegname like- image1.jpg)

//this is the image control where you bind the image
img src='MakeThumbnail.aspx?file="imagename" &h=" + h + " &w=" + w + "' height="200" widht="200"

//Resize function (where width of the image will be fix and the hight of the image will be change according to height

public void resizeimage(string image)
{
System.Drawing.Image img;
try
{
string path = Server.MapPath("imagefolder/" + image);
img = System.Drawing.Image.FromFile(path);
}
catch
{

string path = Server.MapPath("imagefolder/no_img_avai.gif");
img = System.Drawing.Image.FromFile(path);
}

h = img.Height;
w = img.Width;
if (w >= 103)
{

int hei = h * 103;
int he = hei / w;
h = he;
w = 103;

}
else
{
int hei = h * 103;
int he = hei / w;
h = he;
}

}

//MAKE ONE ASPX FILE NAME MakeThumbnail.aspx

using System;
using System.IO;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;

public partial class MakeThumbnail : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
// get the file name -- fall800.jpg
string file = Request.QueryString["file"];
int w = Convert.ToInt32(Request.QueryString["w"]);
int h = Convert.ToInt32(Request.QueryString["h"]);
string filepath = Server.MapPath("imagefolder/" + file.ToString());
// create an image object, using the filename we just retrieved
System.Drawing.Image image = System.Drawing.Image.FromFile(filepath);

// create the actual thumbnail image
System.Drawing.Image thumbnailImage = image.GetThumbnailImage(w, h, new System.Drawing.Image.GetThumbnailImageAbort(ThumbnailCallback), IntPtr.Zero);

// make a memory stream to work with the image bytes
MemoryStream imageStream = new MemoryStream();

// put the image into the memory stream
thumbnailImage.Save(imageStream, System.Drawing.Imaging.ImageFormat.Jpeg);

// make byte array the same size as the image
byte[] imageContent = new Byte[imageStream.Length];

// rewind the memory stream
imageStream.Position = 0;

// load the byte array with the image
imageStream.Read(imageContent, 0, (int)imageStream.Length);

// return byte array to caller with image type
Response.ContentType = "image/jpeg";
Response.BinaryWrite(imageContent);
}
public bool ThumbnailCallback()
{
return true;
}
}

Change color after click on checkbox in grid using javascript

2008-07-08T21:50:00.000-07:00

//Javascript Code
function changeColor(CheckBoxObj)
{
if (CheckBoxObj.checked == true) {
CheckBoxObj.parentNode.parentNode.style.backgroundColor='#88AAFF';
}
else
{
CheckBoxObj.parentNode.parentNode.style.backgroundColor='';
}
}

call it check box onclick event
onclick="changeColor(this);"

Date compare with javascript

2008-07-08T21:22:00.000-07:00

To date must be less than from date

function datevalid(sender, args)
{
var str1 = document.getElementById("txtfrom").value;
var str2 = document.getElementById("txtto").value;
var dt1 = parseInt(str1.substring(0,2),10);
var mon1 = parseInt(str1.substring(3,5),10);
var yr1 = parseInt(str1.substring(6,10),10);
var dt2 = parseInt(str2.substring(0,2),10);
var mon2 = parseInt(str2.substring(3,5),10);
var yr2 = parseInt(str2.substring(6,10),10);
var date1 = new Date(yr1, mon1, dt1);
var date2 = new Date(yr2, mon2, dt2);
if(date2 < date1)
{
document.getElementById('CustomValidator1').innerHTML="From date must be Less than To date";
args.IsValid = false;
return;
}

C# quations - answers

2008-07-08T04:07:00.000-07:00

Good for preparation and general self-testing, but too specific for the actual job interview. This was sent in by a job applicant getting ready to step into the .NET field in India.

Are private class-level variables inherited? - Yes, but they are not accessible, so looking at it you can honestly say that they are not inherited. But they are.
Why does DllImport not work for me? - All methods marked with the DllImport attribute must be marked as public static extern.
Why does my Windows application pop up a console window every time I run it? - Make sure that the target type set in the project properties setting is set to Windows Application, and not Console Application. If you’re using the command line, compile with /target:winexe, not /target:exe.
Why do I get an error (CS1006) when trying to declare a method without specifying a return type? - If you leave off the return type on a method declaration, the compiler thinks you are trying to declare a constructor. So if you are trying to declare a method that returns nothing, use void. The following is an example: // This results in a CS1006 error public static staticMethod (mainStatic obj) // This will work as wanted public static void staticMethod (mainStatic obj)
Why do I get a syntax error when trying to declare a variable called checked? - The word checked is a keyword in C#.
Why do I get a security exception when I try to run my C# app? - Some security exceptions are thrown if you are working on a network share. There are some parts of the frameworks that will not run if being run off a share (roaming profile, mapped drives, etc.). To see if this is what’s happening, just move the executable over to your local drive and see if it runs without the exceptions. One of the common exceptions thrown under these conditions is System.Security.SecurityException. To get around this, you can change your security policy for the intranet zone, code group 1.2, (the zone that running off shared folders falls into) by using the caspol.exe tool.
Why do I get a CS5001: does not have an entry point defined error when compiling? - The most common problem is that you used a lowercase ‘m’ when defining the Main method. The correct way to implement the entry point is as follows: class test { static void Main(string[] args) {} }
What optimizations does the C# compiler perform when you use the /optimize+ compiler option? - The following is a response from a developer on the C# compiler team: We get rid of unused locals (i.e., locals that are never read, even if assigned). We get rid of unreachable code. We get rid of try-catch with an empty try. We get rid of try-finally with an empty try. We get rid of try-finally with an empty finally. We optimize branches over branches: gotoif A, lab1 goto lab2: lab1: turns into: gotoif !A, lab2 lab1: We optimize branches to ret, branches to next instruction, and branches to branches.
What is the syntax for calling an overloaded constructor within a constructor (this() and constructorname() does not compile)? - The syntax for calling another constructor is as follows: class B { B(int i) { } } class C : B { C() : base(5) // call base constructor B(5) { } C(int i) : this() // call C() { } public static void Main() {} }
What is the equivalent to regsvr32 and regsvr32 /u a file in .NET development? - Try using RegAsm.exe. Search MSDN on Assembly Registration Tool.
What is the difference between a struct and a class in C#? - From language spec: The list of similarities between classes and structs is as follows. Longstructs can implement interfaces and can have the same kinds of members as classes. Structs differ from classes in several important ways; however, structs are value types rather than reference types, and inheritance is not supported for structs. Struct values are stored on the stack or in-line. Careful programmers can sometimes enhance performance through judicious use of structs. For example, the use of a struct rather than a class for a Point can make a large difference in the number of memory allocations performed at runtime. The program below creates and initializes an array of 100 points. With Point implemented as a class, 101 separate objects are instantiated-one for the array and one each for the 100 elements.
My switch statement works differently than in C++! Why? - C# does not support an explicit fall through for case blocks. The following code is not legal and will not compile in C#:

13.       switch(x)

14.       {

15.               case 0: // do something

16.               case 1: // do something as continuation of case 0

17.               default: // do something in common with

18.                      //0, 1 and everything else

19.               break;

20.       }

To achieve the same effect in C#, the code must be modified as shown below (notice how the control flows are explicit):

class Test

  public static void Main() {

         int x = 3;

         switch(x)

                 case 0: // do something

                 goto case 1;

                 case 1: // do something in common with 0

                 goto default;

                 default: // do something in common with 0, 1, and anything else

                 break;

Is there regular expression (regex) support available to C# developers? - Yes. The .NET class libraries provide support for regular expressions. Look at the System.Text.RegularExpressions namespace.
Is there any sample C# code for simple threading? - Yes:

23.       using System;

24.       using System.Threading;

25.       class ThreadTest

26.       {

27.               public void runme()

28.               {

29.                      Console.WriteLine("Runme Called");

30.               }

31.               public static void Main(String[] args)

32.               {

33.                      ThreadTest b = new ThreadTest();

34.                      Thread t = new Thread(new ThreadStart(b.runme));

35.                      t.Start();

36.               }

Is there an equivalent of exit() for quitting a C# .NET application? - Yes, you can use System.Environment.Exit(int exitCode) to exit the application or Application.Exit() if it’s a Windows Forms app.
Is there a way to force garbage collection? - Yes. Set all references to null and then call System.GC.Collect(). If you need to have some objects destructed, and System.GC.Collect() doesn’t seem to be doing it for you, you can force finalizers to be run by setting all the references to the object to null and then calling System.GC.RunFinalizers().
Is there a way of specifying which block or loop to break out of when working with nested loops? - The easiest way is to use goto:

40.       using System;

41.       class BreakExample

42.       {

43.               public static void Main(String[] args) {

44.                      for(int i=0; i<3;>

45.                      {

46.                              Console.WriteLine(”Pass {0}: “, i);

47.                              for( int j=0 ; j<100>

48.                              {

49.                                      if ( j == 10)

50.                                             goto done;

51.                                      Console.WriteLine(”{0} “, j);

52.                              }

53.                              Console.WriteLine(”This will not print”);

54.                      }

55.                      done:

56.                              Console.WriteLine(”Loops complete.”);

57.               }

Is it possible to restrict the scope of a field/method of a class to the classes in the same namespace? - There is no way to restrict to a namespace. Namespaces are never units of protection. But if you’re using assemblies, you can use the ‘internal’ access modifier to restrict access to only within the assembly.

.Net & C# Interview question, along with general programming questions

Hey, These are some Interview Questions with suggested answers we collected in Middle-East-Developers, for more questions in other fields like C++, you can check the group.
These questions are collected by

Adel Khalil
Yehia Megahed
Hisham Abd El-Hafez
Mohammed Hossam

Q1: Can DateTime variables be null?
A1: No, because it is a value type (Struct)

Q2: Describe the Asp.net Page Life Cycle?
A2: http://msdn2.microsoft.com/en-us/library/ms178472.aspx

Q3: Describe the Asp.net pipeline ? Give an Example when you need to extend it? How do you do so?
A3: http://msdn.microsoft.com/msdnmag/issues/02/09/HTTPPipelines/

Q4: Describe the accessibility modifier protected internal
A4: Members are accessible to derived classes and classes within the same Assembly

Q5: Difference between an interface and abstract class?
A5: In the interface all methods must be abstract, in the abstract class some methods can be concrete. In the interface no accessibility modifiers are allowed, which is ok in abstract classes.

Q6: How do you perform pre- and post-processing to extend a WebMethod ?
A6: Use SOAP extensions ...http://msdn.microsoft.com/msdnmag/issues/04/03/ASPColumn/

Q7: What are Design Patterns?
A7: It is a big topic in Object Oriented, so for more information see this, http://dofactory.com/Patterns/Patterns.aspx

Q8: What do you know about .net framework 3.0 ?
A8: any answer that introduces Windows Communication Foundation (WCF), Windows Workflow Foundation (WF), Windows Presentation Foundation (WPF) and Windows Card Space (WCS) is right, also you can mention that it was originally called WinFX

Q9: What do you know about ATLAS (Microsoft ASP.net AJAX Extensions) ?
A9: for more information check here, http://ajax.asp.net

Q10: What do you know about Agile software methodologies?
A10: http://en.wikipedia.org/wiki/Agile_software_development

Q11: What do you know about Web Services Enhancements (WSE)?
A11: http://msdn.microsoft.com/webservices/webservices/building/wse/default.aspx

Q12: What is AJAX ?
A12: Asynchronous Javascript And XML

Q13:What is NUnit, or What is Unit testing?
A13: Unit testing: is a procedure used to validate that a particular module of source code is working properly from each modification to the next. The procedure is to write test cases for all functions and methods so that whenever a change causes a regression, it can be quickly identified and fixed. Ideally, each test case is separate from the others; constructs such as mock objects can assist in separating unit tests. This type of testing is mostly done by the developers, NUnit is a famous tool for Unit Testing in .net

Q14: What is an Asp.net Http Handler & Http Module?
A14: http://www.15seconds.com/issue/020417.htm

Q15: What is mutable type ? immutable type ?
A15: Immutable type are types whose instance data, fields and properties, does not change after the instance is created. Most value types are immutable, but the mutable type are A type whose instance data, fields and properties, can be changed after the instance is created. Most Reference Types are mutable.

Q16: What is the HttpContext Object? Where is it accessible?
A16: It's is an Object that Encapsulates all HTTP-specific information about an individual HTTP request. it is avaliable through out the Asp.net request pipline.

Q17: What is the difference between String & StringBuilder classes?
A17: String is an immutable type while StringBuilder is a mutable type

Q18: What's the difference between C# 1.0 & C# 2.0?
A18: Any answer that introduces stuff like, Generics, Anonymous Methods, Nullable types, Iterators ... etc, is correct

Q19: Without using the multiplication or addition operations, how can you multiply a number x by 8?
A19: Shift x to the left 3 times, x <<>

Q20: What is the difference between ASP.net 1.x & ASP.net 2.0 ?
A20: Any answer that include stuff like Provider model (membership provider, role provider ... etc) and Master Pages, Code Beside model, new web controls will be ok.

Dot Net Interview Quations

2008-07-08T03:59:00.000-07:00

What is .NET?
.NET is essentially a framework for software development. It is similar in nature to any other software development framework (J2EE etc) in that it provides a set of runtime containers/capabilities, and a rich set of pre-built functionality in the form of class libraries and APIs
The .NET Framework is an environment for building, deploying, and running Web Services and other applications. It consists of three main parts: the Common Language Runtime, the Framework classes, and ASP.NET.

How many languages .NET is supporting now?
When .NET was introduced it came with several languages. VB.NET, C#, COBOL and Perl, etc. The site DotNetLanguages.Net says 44 languages are supported.

How is .NET able to support multiple languages?
A language should comply with the Common Language Runtime standard to become a .NET language. In .NET, code is compiled to Microsoft Intermediate Language (MSIL for short). This is called as Managed Code. This Managed code is run in .NET environment. So after compilation to this IL the language is not a barrier. A code can call or use a function written in another language.

How ASP .NET different from ASP?
Scripting is separated from the HTML, Code is compiled as a DLL, these DLLs can be executed on the server.

What is smart navigation?
The cursor position is maintained when the page gets refreshed due to the server side validation and the page gets refreshed.

What is view state?
The web is stateless. But in ASP.NET, the state of a page is maintained in the in the page itself automatically. How? The values are encrypted and saved in hidden controls. this is done automatically by the ASP.NET. This can be switched off / on for a single control

How do you validate the controls in an ASP .NET page?
Using special validation controls that are meant for this. We have Range Validator, Email Validator.

Can the validation be done in the server side? Or this can be done only in the Client side?

Client side is done by default. Server side validation is also possible. We can switch off the client side and server side can be done.

Using ActiveX Control in .Net
ActiveX control is a special type of COM component that supports a User Interface. Using ActiveX Control in your .Net Project is even easier than using COM component. They are bundled usually in .ocx files. Again a proxy assembly is made by .Net utility AxImp.exe (which we will see shortly) which your application (or client) uses as if it is a .Net control or assembly.

Making Proxy Assembly For ActiveX Control: First, a proxy assembly is made using AxImp.exe (acronym for ActiveX Import) by writing following command on Command Prompt:

C:> AxImp C:MyProjectsMyControl.ocx
This command will make two dlls, e.g., in case of above command

MyControl.dll
AxMyControl.dll
The first file MyControl.dll is a .Net assembly proxy, which allows you to reference the ActiveX as if it were non-graphical object.

The second file AxMyControl.dll is the Windows Control, which allows u to use the graphical aspects of activex control and use it in the Windows Form Project.

Adding Reference of ActiveX Proxy Assembly in your Project Settings: To add a reference of ActiveX Proxy Assembly in our Project, do this:

o Select Project A Add Reference (Select Add Reference from Project Menu).
o This will show you a dialog box, select .Net tab from the top of window.
o Click Browse button on the top right of window.
o Select the dll file for your ActiveX Proxy Assembly (which is MyControl.dll) and click OK o Your selected component is now shown in the ‘Selected Component’ List Box. Click OK again Some More On Using COM or ActiveX in .Net

.Net only provides wrapper class or proxy assembly (Runtime Callable Wrapper or RCW) for COM or activeX control. In the background, it is actually delegating the tasks to the original COM, so it does not convert your COM/activeX but just imports them.

A good thing about .Net is that when it imports a component, it also imports the components that are publically referenced by that component. So, if your component, say MyDataAcsess.dll references ADODB.dll then .Net will automatically import that COM component too!

The Visual Studio.NET does surprise you in a great deal when u see that it is applying its intellisense (showing methods, classes, interfaces, properties when placing dot) even on your imported COM components!!!! Isn’t it a magic or what?

When accessing thru RCW, .Net client has no knowledge that it is using COM component, it is presented just as another C# assembly.

U can also import COM component thru command prompt (for reference see Professional C# by Wrox)

U can also use your .Net components in COM, i.e., export your .net components (for reference see Professional C# by Wrox)

What is Machine.config?
Machine configuration file: The machine.config file contains settings that apply to the entire computer. This file is located in the %runtime install path%Config directory. There is only one machine.config file on a computer. The Machine.Config file found in the "CONFIG" subfolder of your .NET Framework install directory (c:WINNTMicrosoft.NETFramework{Version Number} CONFIG on Windows 2000 installations). The machine.config, which can be found in the directory $WINDIR$Microsoft.NETFrameworkv1.0.3705CONFIG, is an XML-formatted configuration file that specifies configuration options for the machine. This file contains, among many other XML elements, a browser Caps element. Inside this element are a number of other elements that specify parse rules for the various User-Agents, and what properties each of these parsing supports.

For example, to determine what platform is used, a filter element is used that specifies how to set the platform property based on what platform name is found in the User-Agent string. Specifically, the machine.config file contains:

platform=Win95
platform=Win98
platform=WinNT
...

That is, if in the User-Agent string the string "Windows 95" or "Win95" is found, the platform property is set to Win95. There are a number of filter elements in the browserCaps element in the machine.config file that define the various properties for various User-Agent strings.

Hence, when using the Request.Browser property to determine a user's browser features, the user's agent string is matched up to particular properties in the machine.config file. The ability for being able to detect a user's browser's capabilities, then, is based upon the honesty in the browser's sent User-Agent string. For example, Opera can be easily configured to send a User-Agent string that makes it appear as if it's IE 5.5. In this case from the Web server's perspective (and, hence, from your ASP.NET Web page's perspective), the user is visiting using IE 5.5, even though, in actuality, he is using Opera.

What is Web.config?
In classic ASP all Web site related information was stored in the metadata of IIS. This had the disadvantage that remote Web developers couldn't easily make Web-site configuration changes. For example, if you want to add a custom 404 error page, a setting needs to be made through the IIS admin tool, and you're Web host will likely charge you a flat fee to do this for you. With ASP.NET, however, these settings are moved into an XML-formatted text file (Web.config) that resides in the Web site's root directory. Through Web.config you can specify settings like custom 404 error pages, authentication and authorization settings for the Web sitempilation options for the ASP.NET Web pages, if tracing should be enabled, etc.
The Web.config file is an XML-formatted file. At the root level is the tag. Inside this tag you can add a number of other tags, the most common and useful one being the system.web tag, where you will specify most of the Web site configuration parameters. However, to specify application-wide settings you use the tag.

For example, if we wanted to add a database connection string parameter we could have a Web.config file like so.

What is the difference between ADO and ADO.NET?
ADO uses Recordsets and cursors to access and modify data. Because of its inherent design, Recordset can impact performance on the server side by tying up valuable resources. In addition, COM marshalling - an expensive data conversion process - is needed to transmit a Recordset. ADO.NET addresses three important needs that ADO doesn't address:

1. Providing a comprehensive disconnected data-access model, which is crucial to the Web environment
2. Providing tight integration with XML, and
3. Providing seamless integration with the .NET Framework (e.g., compatibility with the base class library's type system). From an ADO.NET implementation perspective, the Recordset object in ADO is eliminated in the .NET architecture. In its place, ADO.NET has several dedicated objects led by the DataSet object and including the DataAdapter, and DataReader objects to perform specific tasks. In addition, ADO.NET DataSets operate in disconnected state whereas the ADO RecordSet objects operated in a fully connected state.

In ADO, the in-memory representation of data is the RecordSet. In ADO.NET, it is the dataset. A RecordSet looks like a single table. If a RecordSet is to contain data from multiple database tables, it must use a JOIN query, which assembles the data from the various database tables into a single result table. In contrast, a dataset is a collection of one or more tables. The tables within a dataset are called data tables; specifically, they are DataTable objects. If a dataset contains data from multiple database tables, it will typically contain multiple DataTable objects. That is, each DataTable object typically corresponds to a single database table or view. In this way, a dataset can mimic the structure of the underlying database.

In ADO you scan sequentially through the rows of the RecordSet using the ADO MoveNext method. In ADO.NET, rows are represented as collections, so you can loop through a table as you would through any collection, or access particular rows via ordinal or primary key index. A cursor is a database element that controls record navigation, the ability to update data, and the visibility of changes made to the database by other users. ADO.NET does not have an inherent cursor object, but instead includes data classes that provide the functionality of a traditional cursor. For example, the functionality of a forward-only, read-only cursor is available in the ADO.NET DataReader object.

There is one significant difference between disconnected processing in ADO and ADO.NET. In ADO you communicate with the database by making calls to an OLE DB provider. In ADO.NET you communicate with the database through a data adapter (an OleDbDataAdapter, SqlDataAdapter, OdbcDataAdapter, or OracleDataAdapter object), which makes calls to an OLE DB provider or the APIs provided by the underlying data source.

What are Attributes?
Attributes are declarative tags in code that insert additional metadata into an assembly. There exist two types of attributes in the .NET Framework: Predefined attributes such as AssemblyVersion, which already exist and are accessed through the Runtime Classes; and custom attributes, which you write yourself by extending the System.Attribute class.

What are the Types of Assemblies?
Assemblies are of two types:
1. Private Assemblies
2. Shared Assemblies
Private Assemblies: The assembly is intended only for one application. The files of that assembly must be placed in the same folder as the application or in a sub folder. No other application will be able to make a call to this assembly. The advantage of having a private assembly is that, it makes naming the assembly very easy, since the developer need not worry about name clashes with other assemblies. As long as the assembly has a unique name within the concerned application, there won't be any problems.
Shared Assemblies: If the assembly is to be made into a Shared Assembly, then the naming conventions are very strict since it has to be unique across the entire system. The naming conventions should also take care of newer versions of the component being shipped. These are accomplished by giving the assembly a Shared Name. Then the assembly is placed in the global assembly cache, which is a folder in the file system reserved for shared assemblies.

What is an Intermediate language?
Assemblies are made up of IL code modules and the metadata that describes them. Although programs may be compiled via an IDE or the command line, in fact, they are simply translated into IL, not machine code. The actual machine code is not generated until the function that requires it is called. This is the just-in-time, or JIT, compilation feature of .NET. JIT compilation happens at runtime for a variety of reasons, one of the most ambitious being Microsoft's desire for cross-platform .NET adoption. If a CLR is built for another operating system (UNIX or Mac), the same assemblies will run in addition to the Microsoft platforms. The hope is that .NET assemblies are write-once-run-anywhere applications. This is a .NET feature that works behind-the-scenes, ensuring that developers are not limited to writing applications for one single line of products. No one has demonstrated whether or not this promise will ever truly materialize.

CTS/CLS

The MSIL Instruction Set Specification is included with the .NET SDK, along with the IL Assembly Language Programmers Reference. If a developer wants to write custom .NET programming languages, these are the necessary specifications and syntax. The CTS and CLS define the types and syntaxes that every .NET language needs to embrace. An application may not expose these features, but it must consider them when communicating through IL.

ASP.NET Authentication Providers and IIS Security

ASP.NET implements authentication using authentication providers, which are code modules that verify credentials and implement other security functionality such as cookie generation. ASP.NET supports the following three authentication providers:

Forms Authentication: Using this provider causes unauthenticated requests to be redirected to a specified HTML form using client side redirection. The user can then supply logon credentials, and post the form back to the server. If the application authenticates the request (using application-specific logic), ASP.NET issues a cookie that contains the credentials or a key for reacquiring the client identity. Subsequent requests are issued with the cookie in the request headers, which means that subsequent authentications are unnecessary.

Passport Authentication: This is a centralized authentication service provided by Microsoft that offers a single logon facility and membership services for participating sites. ASP.NET, in conjunction with the Microsoft® Passport software development kit (SDK), provides similar functionality as Forms Authentication to Passport users.

Windows Authentication: This provider utilizes the authentication capabilities of IIS. After IIS completes its authentication, ASP.NET uses the authenticated identity's token to authorize access.

To enable a specified authentication provider for an ASP.NET application, you must create an entry in the application's configuration file as follows:
// web.config file

What is the difference between ASP and ASP.NET?
ASP is interpreted. ASP.NET Compiled event base programming.
Control events for text button can be handled at client javascript only. Since we have server controls events can handle at server side.
More error handling.

ASP .NET has better language support, a large set of new controls and XML based components, and better user authentication.

ASP .NET provides increased performance by running compiled code.

ASP .NET code is not fully backward compatible with ASP.

ASP .NET also contains a new set of object oriented input controls, like programmable list boxes, validation controls. A new data grid control supports sorting, data paging, and everything you expect from a dataset control. The first request for an ASP.NET page on the server will compile the ASP .NET code and keep a cached copy in memory. The result of this is greatly increased performance.

ASP .NET is not fully compatible with earlier versions of ASP, so most of the old ASP code will need some changes to run under ASP .NET. To overcome this problem,

ASP .NET uses a new file extension ".aspx". This will make ASP .NET applications able to run side by side with standard ASP applications on the same server.

Using COM Component in .Net ?
As most of you know that .Net does not encourage the development of COM components and provides a different solution to making reusable components through Assemblies. But, there are a lot of COM components present which our .Net application might need to use. Fortunately, .Net provides an extremely simple approach to achieve this. This is achieved by using ‘Wrapper Classes’ and ‘Proxy Components’. .Net wraps the COM component into .Net assembly technically called ‘Runtime Callable Wrapper’ or RCW. Then u can call and use your COM component just as a .Net (or C#, if u are using C#) Assembly.

What is an assembly?
An assembly is the primary building block of a .NET Framework application. It is a collection of functionality that is built, versioned, and deployed as a single implementation unit (as one or more files). All managed types and resources are marked either as accessible only within their implementation unit, or as accessible by code outside that unit. .NET Assembly contains all the metadata about the modules, types, and other elements it contains in the form of a manifest. The CLR loves assemblies because differing programming languages are just perfect for creating certain kinds of applications. For example, COBOL stands for Common Business-Oriented Language because it’s tailor-made for creating business apps. However, it’s not much good for creating drafting programs. Regardless of what language you used to create your modules, they can all work together within one Portable Executable Assembly. There’s a hierarchy to the structure of .NET code. That hierarchy is Assembly - > Module -> Type -> Method." Assemblies can be static or dynamic. Static assemblies can include .NET Framework types (interfaces and classes), as well as resources for the assembly (bitmaps, JPEG files, resource files, and so on). Static assemblies are stored on disk in portable executable (PE) files. You can also use the .NET Framework to create dynamic assemblies, which are run directly from memory and are not saved to disk before execution. You can save dynamic assemblies to disk after they have executed.

What is a Web Service?
A web service is a software component that exposes itself through the open communication channels of the Internet. Applications running on remote machines, on potentially different platforms, can access these components in a language and platform-independent manner. A Web Service is a group of functions, packaged together for use in a common framework throughout a network.

webFarm Vs webGardens
A web farm is a multi-server scenario. So we may have a server in each state of US. If the load on one server is in excess then the other servers step in to bear the brunt.
How they bear it is based on various models.
1. RoundRobin. (All servers share load equally)
2. NLB (economical)
3. HLB (expensive but can scale up to 8192 servers)
4. Hybrid (of 2 and 3).
5. CLB (Component load balancer).
A web garden is a multi-processor setup. i.e., a single server (not like the multi server above).
How to implement webfarms in .Net:
Go to web.config and Here for mode = you have 4 options.
a) Say mode=inproc (non web farm but fast when you have very few customers).
b) Say mode=StateServer (for webfarm)
c) Say mode=SqlServer (for webfarm)
Whether to use option b or c depends on situation. StateServer is faster but SqlServer is more reliable and used for mission critical applications.
How to use webgardens in .Net:
Go to web.config and Change the false to true. You have one more attribute that is related to webgarden in the same tag called cpuMask.

What is the difference between a namespace and assembly name?
A namespace is a logical naming scheme for types in which a simple type name, such as MyType, is preceded with a dot-separated hierarchical name. Such a naming scheme is completely under control of the developer. For example, types MyCompany.FileAccess.A and MyCompany.FileAccess.B might be logically expected to have functionally related to file access. The .NET Framework uses a hierarchical naming scheme for grouping types into logical categories of related functionality, such as the ASP.NET application framework, or remoting functionality. Design tools can make use of namespaces to make it easier for developers to browse and reference types in their code. The concept of a namespace is not related to that of an assembly. A single assembly may contain types whose hierarchical names have different namespace roots, and a logical namespace root may span multiple assemblies. In the .NET Framework, a namespace is a logical design-time naming convenience, whereas an assembly establishes the name scope for types at run time.

What’s a Windows process?
It’s an application that’s running and had been allocated memory.

What’s typical about a Windows process in regards to memory allocation?
Each process is allocated its own block of available RAM space, no process can access another process’ code or data. If the process crashes, it dies alone without taking the entire OS or a bunch of other applications down.

Explain what relationship is between a Process, Application Domain, and Application?
Each process is allocated its own block of available RAM space, no process can access another process’ code or data. If the process crashes, it dies alone without taking the entire OS or a bunch of other applications down.
A process is an instance of a running application. An application is an executable on the hard drive or network. There can be numerous processes launched of the same application (5 copies of Word running), but 1 process can run just 1 application.

What are possible implementations of distributed applications in .NET?
.NET Remoting and ASP.NET Web Services. If we talk about the Framework Class Library, noteworthy classes are in System.Runtime.Remoting and System.Web.Services.

What are the consideration in deciding to use .NET Remoting or ASP.NET Web Services?
Remoting is a more efficient communication exchange when you can control both ends of the application involved in the communication process. Web Services provide an open-protocol-based exchange of information. Web Services are best when you need to communicate with an external organization or another (non-.NET) technology.

What’s a proxy of the server object in .NET Remoting?
It’s a fake copy of the server object that resides on the client side and behaves as if it was the server. It handles the communication between real server object and the client object. This process is also known as marshaling.

What are remotable objects in .NET Remoting?
Remotable objects are the objects that can be marshaled across the application domains. You can marshal by value, where a deep copy of the object is created and then passed to the receiver. You can also marshal by reference, where just a reference to an existing object is passed.

What are channels in .NET Remoting?
Channels represent the objects that transfer the other serialized objects from one application domain to another and from one computer to another, as well as one process to another on the same box. A channel must exist before an object can be transferred.

What security measures exist for .NET Remoting in System.Runtime.Remoting?
None. Security should be taken care of at the application level. Cryptography and other security techniques can be applied at application or server level.

What is a formatter?
A formatter is an object that is responsible for encoding and serializing data into messages on one end, and deserializing and decoding messages into data on the other end.

Choosing between HTTP and TCP for protocols and Binary and SOAP for formatters, what are the trade-offs?
Binary over TCP is the most effiecient, SOAP over HTTP is the most interoperable.

What’s SingleCall activation mode used for?
If the server object is instantiated for responding to just one single request, the request should be made in SingleCall mode.

What’s Singleton activation mode?
A single object is instantiated regardless of the number of clients accessing it. Lifetime of this object is determined by lifetime lease.

How do you define the lease of the object?
By implementing ILease interface when writing the class code.

Can you configure a .NET Remoting object via XML file?
Yes, via machine.config and application level .config file (or web.config in ASP.NET). Application-level XML settings take precedence over machine.config.

How can you automatically generate interface for the remotable object in .NET with Microsoft tools?
Use the Soapsuds tool.

What is Delegation?
A delegate acts like a strongly type function pointer. Delegates can invoke the methods that they reference without making explicit calls to those methods.
Delegate is an entity that is entrusted with the task of representation, assign or passing on information. In code sense, it means a Delegate is entrusted with a Method to report information back to it when a certain task (which the Method expects) is accomplished outside the Method's class.

What is "Microsoft Intermediate Language" (MSIL)?
A .NET programming language (C#, VB.NET, J# etc.) does not compile into executable code; instead it compiles into an intermediate code called Microsoft Intermediate Language (MSIL). As a programmer one need not worry about the syntax of MSIL - since our source code in automatically converted to MSIL. The MSIL code is then send to the CLR (Common Language Runtime) that converts the code to machine language, which is, then run on the host machine. MSIL is similar to Java Byte code. MSIL is the CPU-independent instruction set into which .NET Framework programs are compiled. It contains instructions for loading, storing, initializing, and calling methods on objects. Combined with metadata and the common type system, MSIL allows for true cross- language integration Prior to execution, MSIL is converted to machine code. It is not interpreted.

Differences between Datagrid, Datalist and Repeater?
1. Datagrid has paging while Datalist doesnt.
2. Datalist has a property called repeat. Direction = vertical/horizontal. (This is of great help in designing layouts). This is not there in Datagrid.
3. A repeater is used when more intimate control over html generation is required.
4. When only checkboxes/radiobuttons are repeatedly served then a checkboxlist or radiobuttonlist are used as they involve fewer overheads than a Datagrid.
The Repeater repeats a chunk of HTML you write, it has the least functionality of the three. DataList is the next step up from a Repeater; accept you have very little control over the HTML that the control renders. DataList is the first of the three controls that allow you Repeat-Columns horizontally or vertically. Finally, the DataGrid is the motherload. However, instead of working on a row-by-row basis, you’re working on a column-by-column basis. DataGrid caters to sorting and has basic paging for your disposal. Again you have little contro, over the HTML. NOTE: DataList and DataGrid both render as HTML tables by default. Out of the 3 controls, I use the Repeater the most due to its flexibility w/ HTML. Creating a Pagination scheme isn't that hard, so I rarely if ever use a DataGrid.
Occasionally I like using a DataList because it allows me to easily list out my records in rows of three for instance.

I am constantly writing the drawing procedures with System.Drawing.Graphics, but having to use the try and dispose blocks is too time-consuming with Graphics objects. Can I automate this?
Yes, the code

System.Drawing.Graphics canvas = new System.Drawing.Graphics();
try
{
//some code
}
finally
canvas.Dispose();

is functionally equivalent to

using (System.Drawing.Graphics canvas = new System.Drawing.Graphics())
{
//some code
} //canvas.Dispose() gets called automatically

How do you trigger the Paint event in System.Drawing?
Invalidate the current form, the OS will take care of repainting. The Update method forces the repaint.

With these events, why wouldn’t Microsoft combine Invalidate and Paint, so that you wouldn’t have to tell it to repaint, and then to force it to repaint?
Painting is the slowest thing the OS does, so usually telling it to repaint, but not forcing it allows for the process to take place in the background.

How can you assign an RGB color to a System.Drawing.Color object?
Call the static method FromArgb of this class and pass it the RGB values.

What class does Icon derive from? Isn’t it just a Bitmap with a wrapper name around it?
No, Icon lives in System.Drawing namespace. It’s not a Bitmap by default, and is treated separately by .NET. However, you can use ToBitmap method to get a valid Bitmap object from a valid Icon object.

Before in my VB app I would just load the icons from DLL. How can I load the icons provided by .NET dynamically?
By using System.Drawing.SystemIcons class, for example System.Drawing.SystemIcons.Warning produces an Icon with a warning sign in it.

When displaying fonts, what’s the difference between pixels, points and ems?
A pixel is the lowest-resolution dot the computer monitor supports. Its size depends on user’s settings and monitor size. A point is always 1/72 of an inch. An em is the number of pixels that it takes to display the letter M.

What is the difference between VB 6 and VB.NET?
Answer1
VB

1,Object-based Language
2,Doesnot support Threading
3,Not powerful Exception handling mechanism
4,Doesnot having support for the console based applications
5,Cannot use more than one version of com objects in vb application called DLL error
6,Doesnot support for the Disconnected data source.

VB.Net

1,Object-oriented Language
2,supports Threading
3,powerful Exception handling mechanism
4,having support for the console based applications
5,More than one version of dll is supported
6,supports the Disconnected data source by using Dataset class

Answer2
VB:
1. Object-based language
2. Does not support inheritance
3. ADO.Net does not give support for disconnected data architecture
4. No interoperability function
5. No support for threading

VB.Net
1. Object-Oriented Programming lanugage
2. ADO.Net gives support for disconnected data architecture
3. It provides interoperability
4. It uses managed code
5. supports threading
6. provides access to third-party controls like COM, DCOM

Answer2
1.The concept of the complete flow of execution of a program from start to finish: Visual Basic hides this aspect of programs from you, so that the only elements of a Visual Basic program you code are the event handlers and any methods in class modules. C# makes the complete program available to you as source code. The reason for this has to do with the fact that C# can be seen, philosophically, as next-generation C++. The roots of C++ go back to the 1960s and predate windowed user interfaces and sophisticated operating systems. C++ evolved as a low-level, closeto- the-machine, all-purpose language. To write GUI applications with C++ meant that you had to invoke the system calls to create and interact with the windowed forms. C# has been designed to build on this tradition while simplifying and modernizing C++, to combine the low-level performance benefits of C++ with the ease of coding in Visual Basic. Visual Basic, on the other hand, is designed specifically for rapid application development of Windows GUI applications. For this reason, in Visual Basic all the GUI boilerplate code is hidden, and all the Visual Basic programmer implements are the event handlers. In C# on the other hand, this boilerplate code is exposed as part of your source code.
2. Classes and inheritance: C# is a genuine object-oriented language, unlike Visual Basic, requiring all code to be a part of a class. It also includes extensive support for implementation inheritance. Indeed, most well-designed C# programs will be very much designed around this form of inheritance, which is completely absent in Visual Basic.

What are the authentication methods in .NET?
There are 4 types of authentications.
1.WINDOWS AUTHENTICATION
2.FORMS AUTHENTICATION
3.PASSPORT AUTHENTICATION
4.NONE/CUSTOM AUTHENTICATION

The authentication option for the ASP.NET application is specified by using the tag in the Web.config file, as shown below:
other authentication options
1. WINDOWS AUTHENTICATION Schemes
I. Integrated Windows authentication
II. Basic and basic with SSL authentication
III. Digest authentication
IV. Client Certificate authentication

2. FORMS AUTHENTICATION
You, as a Web application developer, are supposed to develop the Web page and authenticate the user by checking the provided user ID and password against some user database

3.PASSPORT AUTHENTICATION
A centralized service provided by Microsoft, offers a single logon point for clients. Unauthenticated users are redirected to the Passport site

4 NONE/CUSTOM AUTHENTICATION:
If we don’t want ASP.NET to perform any authentication, we can set the authentication mode to “none”. The reason behind this decision could be: We don’t want to authenticate our users, and our Web site is open for all to use. We want to provide our own custom authentication

What is Serialization in .NET?
Anwer1
The serialization is the process of converting the objects into stream of bytes.
they or used for transport the objects(via remoting) and persist objects(via files and databases)

Answer2
When developing smaller applications that do not have a database (or other formal storage mechanism) or data that doesn’t need to be stored in a database (such as the state of a web application), you often still would like to save the data for later retrieval. There are many ways to do this, but many of them are subject to a lot of extra code (work) and extra time spent debugging. With .NET, there is now an easy way to add this functionality to your code with only a few lines of easily tested code. This easy way is called serialization.

Serialization is the process of storing an object, including all of its public and private fields, to a stream. Deserialization is the opposite – restoring an object’s field values from a stream. The stream is generally in the form of a FileStream, but does not have to be. It could be a memory stream or any other object that is of type IO.Stream. The format can be anything from XML to binary to SOAP.

What’s the use of System.Diagnostics.Process class?
By using System.Diagnostics.Process class, we can provide access to the files which are presented in the local and remote system.
Example: System.Diagnostics.Process(”c:\mlaks\example.txt”) — local file
System.Diagnostics.Process(”http://www.mlaks.com\example.txt”) — remote file

What are the authentication methods in .NET?
Abstract class: This class has abstract methods (no body). This class cannot be instantiated. One needs to provide the implementation of the methods by overriding them in the derived class. No Multiple Inheritance.
Interfaces: Interface class contains all abstract methods which are public by default. All of these methods must be implemented in the derived class. One can inherit from from more than one interface thus provides for Multiple Inheritance.

re-clarification of object based:
VB6 DOES support polymorphism and interface inheritance. It also supports the “Implements” keyword. What is not supported in vb6 is implementation inheritance.
Also, from above, vb6 DOES “provides access to third-party controls like COM, DCOM ” That is not anything new in .NET.

How to achieve Polymorphism in VB.Net?
We can achieve polymarphism in .Net i.e Compile time polymarphism and Runtime polymarphism. Compiletime Polymarphism achieved by method overloading. Runtime polymarphism achieved by Early Binding or Late Binding. Provide the function pointer to the object at compile time called as Early Binding.
provide the function pointer to the object at runtime called as Late Binding
class emp having the method display()
class dept having the method display()

create objects as in the main function
// Early binding
dim obj as new emp
dim ob as new dept

obj.display()-to call the display method of emp class
ob.display-to call the display method of the dept class
// Late binding

create object in the main class as
object obj
obj=new emp
obj.display()-to call the display of emp class
obj=new dept
obj.display()-to call the display of dept class

Difference between Class And Interface
Class is logical representation of object. It is collection of data and related sub procedures with defination.
Interface is also a class containg methods which is not having any definations.
Class does not support multiple inheritance. But interface can support.

What doesu mean by .NET framework?
The .NET Framework is an environment for building, deploying, and running Web Services and other applications. It consists of three main parts: the Common Language Runtime, the Framework classes, and ASP.NET

What is assembly?
It is a single deployable unit that contains all the information abt the implimentation of classes , stuctures and interfaces

What is namespaces?
It is a logical group of related classes and interfaces and that can be used byany language targeting the .net framework.

.NET framework programming interview questions

.NET framework overview
1. Has own class libraries. System is the main namespace and all other namespaces are subsets of this.
2. It has CLR(Common language runtime, Common type system, common language specification)
3. All the types are part of CTS and Object is the base class for all the types.
4. If a language said to be .net complaint, it should be compatible with CTS and CLS.
5. All the code compiled into an intermediate language by the .Net language compiler, which is nothing but an assembly.
6. During runtime, JIT of CLR picks the IL code and converts into PE machine code and from there it processes the request.
7. CTS, CLS, CLR
8. Garbage Collection
9. Dispose, finalize, suppress finalize, Idispose interface
10. Assemblies, Namespace: Assembly is a collection of class/namespaces. An assembly contains Manifest, Metadata, Resource files, IL code
11. Com interoperability, adding references, web references
12. Database connectivity and providers

Application Domain
1. Class modifiers: public, private, friend, protected, protected friend, mustinherit, NotInheritable
2. Method modifiers: public, private
3. Overridable
4. Shadows
5. Overloadable
6. Overrides
7. Overloads
8. Set/Get Property
9. IIF
10. Inheritance
11. Polymorphism
12. Delegates
13. Events
14. Reflection
15. Boxing
16. UnBoxing

ASP.Net
1. Web Controls: Data grid (templates, sorting, paging, bound columns, unbound columns, data binding), Data list, repeater controls
2. HTML Controls
3. Code behind pages, system.web.ui.page base class
4. Web.config: App settings, identity (impersonate), authentication (windows, forms, anonymous, passport), authorization
5. Databind.eval
6. Trace, Debug
7. Output cache
8. Session management
9. Application, Session
10. Global.asax httpapplication
11. User controls, custom controls, custom rendered controls (postback event, postdatachanged event) usercontrol is the base class
12. Directives

ADO.Net
1. Command object (ExecuteNonquery, ExecuteReader, ExecuteXMLReader, ExecuteScalar)
2. DataAdapter object (Fill)
3. Dataset (collection of tables)
4. CommandBuiler object
5. Transaction Object
6. Isolation levels

How execute store procedure with C#.net

2008-07-08T02:40:00.000-07:00

Create store procedure in sql query analyser

CREATE PROCEDURE sp_chkadmin
@login_id varchar(50),
@password varchar(50)
as begin
select * from where login_id = @login_id and password =@password
end

GO

protected void butlogin_ServerClick1(object sender, EventArgs e)
{

string username = txtlogin.Value.ToString().Replace("'", "''");
string password = txtpassword.Value.ToString().Replace("'", "''");
int isUserExist=0;
isUserExist = IsUserExist(username, password);
if (isUserExist == 1)
{
Session["admin"] = username;
Response.Redirect("next.aspx");
}
else
{
lblhead.Text = "Please Enter Correct Username or Password !";
lblhead.Visible = true;
}

}

public int IsUserExist(string id,string pass)
{
string CONN_STRING = System.Configuration.ConfigurationSettings.AppSettings["urlString"]
.ToString();//"provider=sqloledb;server=aaa;uid=aa;pwd=aa;";
SqlConnection conn = new SqlConnection(CONN_STRING);
SqlCommand cmd = new SqlCommand();
SqlDataAdapter da = new SqlDataAdapter();
DataSet ds =new DataSet() ;

int iRows = 0;
try
{
cmd.Connection = conn;
if (conn.State == ConnectionState.Closed) conn.Open();
// conn.Open();
cmd.Parameters.Clear();

cmd.CommandType = CommandType.StoredProcedure;
cmd.CommandText = "sp_chkadmin";

cmd.Parameters.Add(new SqlParameter("@login_id", SqlDbType.VarChar));
cmd.Parameters["@login_id"].Value = id;

cmd.Parameters.Add(new SqlParameter("@password", SqlDbType.VarChar));
cmd.Parameters["@password"].Value = pass;

da.SelectCommand = cmd;
iRows = Convert.ToInt32(cmd.ExecuteScalar());
}
catch (Exception ex)
{

}
finally
{
if (conn.State == ConnectionState.Open) conn.Close();
}
return iRows;
}