DELEGATES

• It’s used to represent or refer one or more functions
• Delegates are user defined types in C#.NET
• Delegates in C#.NET are similar to function pointers in C++
• It’s not a member of a class, but similar to a class
• To consume any delegate, we need to create an object to delegate
• A delegate is a type that references a method
• Once a delegate method can be invoked like any other method with parameters and written value
• These can be used to define callback methods
• These are the backbone for events
• These can be chained together, i.e. ,multiple methods can be called on a single event

 Types of Delegates

There are of two types of Delegates available

1) Single class delegate      2) Multi cast delegate

• A delegate that represents only a single function is known as Single Cast Delegate
• A delegate that represents only a more than more than one functions is known as Multi Cast Delegate
• Delegates will support  Generics
• In C#.NET 2.0 Version, a new feature of Delegate is introduced in Anonmous Delegate
• Delegate are obj.oriented, types are and secure

To Work With Delegate Use The Following Steps

1. Creating a Delegate
2. Instantiating a Delegate
3. Invoking a Delegate

Ex: If we consider a function, like…,

        Public void Add

      {

           Code…

      }

To refer this function, if we want to use the delegate, we use the above steps like…

STEP 1: Creating A Delegate

Syntax: Access modifier delegate return type Delegate name ([arguments list]);

Ex: public delegate void Sample Delegate (int x, int y);

• When we create a delegate, Access modifier, return type , number of arguments and their data types of the delegate must and should be same as Access Modifier, return type, number of arguments and their data types of the function that we want to refer

STEP 2: Instantiating the Delegate

 Syntax: Delegate name object name=new Delegate name(Target function name);

 Ex: SampleDelegate obj =new SampleDelegate(Add);

• At this step a reference will be maintained from the delegate object to the function that we want to refer

STEP 3: Invoking the Delegate

Syntax: Object Name([Arguments values])

Ex: Obj(10,20)

• At this step the function that is referred by the delegate will be called for the execution