Here, I tried to cover interfaces in my own words:

Interface

An interface is simply a collection of function prototypes. An Interface is a reference type like a class, but interface can contain only abstract members. In other words, Interface is a contract that defines the signature of the functionality.

An interface looks like a class definitions, but its only purpose is to define a set of methods and not to implement them. For this reason the interface definition includes only the definition of methods [in other words the abstract methods]. Interface contains only methods, properties and delegates but can not contain fields, constructors, destructor and any type of static members.

For more details and example refer to : http://gauravarora.indiamentor.com/Chapters/csharplanguageii.htm

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Structures

A structure in C# is simply a composite data type [you are well aware from composite data type, refer to data types for more details], which consists number of members of other types. The structure define simply by using the struct keyword.

eg. struct enroll
{
   public string name, fname, mname;
   public string char sex;
   Public int age;
   public string address;
}

Classes

It is cleared from above study that Classes are reference type. A class is a collection of its data members. Data members are those members of class which contains the data of class like fields, constants and events etc. Class is declared simply just followed by class keyword with optional modifiers; by default C# classes are public.

eg. class myClass
{
   public int xyz;
   public string name;
   public const int y=22;
}

Look into more details at : http://gauravarora.indiamentor.com/Chapters/csharplanguageii.htm

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1. Can I inherit two difference classes to partial classes?
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I have two classes XYZ and ABC and two partial classes  of class myClass now is it possible:

partial class myClass : XYZ

{

}

partial class myClass : ABC

{

}

Ans:  This question I have asked in RSystems, Noida and I am sharing hereunder with you :

We can’t inherit two difference classes to partial class because in C# multiple inheritance is not possible using classes.

The main reason is in C# we cant do the following:

class myClass : XYZ, ABC

{

}

It will throw an error while we compile the code.

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Can we create a singleton class using public constructor?

Simply answer is yes.

Practically, many of us aware that we can create a singleton class by using private constructor an creating a property, but we can create a singleton class by using public constructor as folows:

static void Main(string[] args)

{

try

{

Singleton obj3 = new Singleton2();

Singleton obj4 = new Singleton2();

Console.Read();

}

catch (Exception ex)

{

Console.WriteLine(ex.ToString());

Console.Read();

}

}

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3. Define Lambda expressions

Left side of this operator specifies the input parameters and contains the expression or statement block at the right side.

Example: myExp = myExp/10;

Now, let see how we can assign the above to a delegate and create an expression tree:

delegate int myDel(int intMyNum);
static void Main(string[] args)
{
//assign lambda expression to a delegate:
myDel myDelegate = myExp => myExp / 10;
int intRes = myDelegate(110);
Console.WriteLine("Output {0}", intRes);
Console.ReadLine();
//Create an expression tree type
//This needs System.Linq.Expressions
Expression<myDel> myExpDel = myExp => myExp /10;
}

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Its just a collection items not child items and are not render while anyone put some html tags. So, its not possible

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A Lambda expression is nothing but an Anonymous Function, can contain expressions and statements. Lambda expressions can be used mostly to create delegates or expression tree types. Lambda expression uses lambda operator => and read as ‘goes to’ operator.

Left side of this operator specifies the input parameters and contains the expression or statement block at the right side.

Example:  myExp = myExp/10;

Now, let see how we can assign the above to a delegate and create an expression tree:

delegate int myDel(int intMyNum);

static void Main(string[] args)

{

//assign lambda expression to a delegate:

myDel myDelegate = myExp => myExp / 10;

int intRes = myDelegate(110);

Console.WriteLine(“Output {0}”, intRes);

Console.ReadLine();

//Create an expression tree type

//This needs System.Linq.Expressions

Expression<myDel> myExpDel = myExp => myExp /10;

}

Note:

The => operator has the same precedence as assignment (=) and is right-associative.

Lambdas are used in method-based LINQ queries as arguments to standard query operator methods such as Where.

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<object classid=”clsid:D27CDB6E-AE6D-11cf-96B8-444553540000″ id=”name” width=”468″ codebase=”http://active.macromedia.com/flash4/cabs/swflash.cab#version=4,0,0,0″ height=”60″>
<param value=”http://www.msdotnetheaven.com/shubhhostingDiwali.swf” name=”movie”/>
<param value=”high” name=”quality”/>
<param value=”transparent” name=”wmode”/>
<embed
pluginspage=”http://www.macromedia.com/shockwave/download/index.cgi?
P1_Prod_Version=ShockwaveFlash” quality=”high” type=”application/x-shockwave-flash” height=”60″ src=”http://www.msdotnetheaven.com/shubhhostingDiwali.swf” width=”468″ wmode=”transparent” name=”name”>
</embed>
</object>

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By default width of column handled automatically, means columns in Gridview control are sized automaticlaly internally column cells redered as HTML cell. On the basis of requirement one can set the width dynamically also.

Following are the steps to do it;

1. Setting Column Width Dynamically:

Through code, set the width property on the ItemStyle of GridView.

Following is the code-snippet for the same:

VB.NEt:

Dim intColWidth As Integer = 25

GridView1.Columns(0).ItemStyle.Width = intColWidth

C#:

int intColWidth = 25;

GridView1.Columns(0).ItemStyle.Width = intColWidth;

2. Setting Column width as per Data-Content :

Write following piece of code in RowDataBound handler / event:

Note: Code is taken from MSDn for reference purpose only:

VB.NET:

Protected widestData As Integer

Protected Sub GridView1_RowDataBound(ByVal sender As Object, _

ByVal e As System.Web.UI.WebControls.GridViewRowEventArgs)

Dim drv As System.Data.DataRowView

drv = CType(e.Row.DataItem, System.Data.DataRowView)

If e.Row.RowType = DataControlRowType.DataRow Then

If drv IsNot Nothing Then

Dim catName As String = drv(1).ToString()

Dim catNameLen As Integer = catName.Length

If catNameLen > widestData Then

widestData = catNameLen

GridView1.Columns(2).ItemStyle.Width = _

widestData * 30

GridView1.Columns(2).ItemStyle.Wrap = False

End If

End If

End If

End Sub

Protected Sub Page_Load(ByVal sender As Object, _

ByVal e As System.EventArgs) Handles Me.Load

widestData = 0

End Sub

C#:

protected int widestData;

protected void GridView1_RowDataBound(object sender, System.Web.UI.WebControls.GridViewRowEventArgs e)

{

System.Data.DataRowView drv = default(System.Data.DataRowView);

drv = (System.Data.DataRowView)e.Row.DataItem;

if (e.Row.RowType == DataControlRowType.DataRow) {

if (drv != null) {

string catName = drv(1).ToString();

int catNameLen = catName.Length;

if (catNameLen > widestData) {

widestData = catNameLen;

GridView1.Columns(2).ItemStyle.Width = widestData * 30;

GridView1.Columns(2).ItemStyle.Wrap = false;

}

}

}

}

protected void  // ERROR: Handles clauses are not supported in C#

Page_Load(object sender, System.EventArgs e)

{

widestData = 0;

}

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