Delegates in C#


A delegate is a type-safe function pointer that can reference a method that has the same signature as that of a delegate.
In short: Rather than pointing to the actual function, you point to a delegate.

Delegates :


  • Used to define callback methods 
  • Implement event handling
  • Declared using "delegate" keyword. 
  • It allows us to pass methods as parameter. 
Types of Delegates: 
  • Simple/Single Delegate - When delegate takes reference with single method. 
  • Multicast Delegate - When delegates takes reference with multiple methods. You can make use + and\or (-) sign to add and subtract methods respectively. This creates an invocation list and is called upon the order of addition. 
  • Generic Delegate 

Different ways of creating a delegate in C#: 
  • Action - Action takes up to 16 input Parameters and doesn't return a value.
    • Example: delegate int Action(T1 arg1, T2 arg2); 
  • Func
  • Predicate
  • Lambda
  • Anonymous Types.
Fun Facts:
     You can point to multiple methods and these are called multicast delegates. 
     Delegates in C# are similar to C++ function pointer.
     Delegates can be used to point to a static method or an instance method.  

More about delegates and code in the next section.

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