How delegates work (in the background)?

Question

How do delegates work in c# behind the scenes and how can they be used efficiently?

EDIT: I know how they work on the surface(they are basically function pointers a

Answer 1

C# delegates are objects (check the System.Delegate class) that encapsulate a reference to an object and a method pointer. They can also have a null reference to object to represent a call to a static method.

When invoking the delegate with arguments, the delegate crafts a call to the referenced method on referenced object with specified arguments.

A compiled delegate Invoke method is directly handled by the runtime (as visible with Reflector):

[MethodImpl(0, MethodCodeType=MethodCodeType.Runtime)]
public virtual void Invoke(T obj);

The runtime use all the info internaly to compile a standard method call to the referenced method.