Declaring a Delegate

A delegate is a special type that can store a function. When you declare a delegate you tell the compiler what types of functions your delegate is meant to store. The delegate declaration itself looks just like a function declaration but with the delegate keyword in front.

To declare a delegate:

1. Either outside of a class or inside of a class type delegate .

2. Write a function prototype; that is, type a return type, followed by a function name , followed by input parameters.

3. Type a semicolon ; ( Figure 10.5 ).

   Figure 10.5 A delegate looks like a function declaration, except that the compiler turns the declaration into an entire class. The class name will be TaskDel, therefore TaskDel becomes a new data type.

    delegate bool TaskDel(string desc); 

Tips

• Just like other function declarations, delegates can either return void, or any other type.

• At first glance it may look strange to throw a declaration of a delegate outside of a class, but the compiler takes that one line and creates a whole class out of it, so in essence what you are doing is declaring a new class. The class that it creates is derived from System.MulticastDelegate.