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**DELEGATE**

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A** DELEGATE **is equivalent to function pointers (i.e., [[callback functions.htm|callback functions]]), but object-oriented and type safe. Type safe means that if the function signature implemented by the Client differs in terms of number of parameters or parameter types or return values as opposed to the method signature, it is going to //safely// raise an error.

So a Delegate provides the feature of Callback functions in a safe way. In Clarion#, the DELEGATE keyword is used in the MAP prototype, and the EVENT keyword is also needed for the target method. The delegate is actually declared as a PROCEDURE DELEGATE in the PROGRAM MAP structure.

In summary, a delegate is a managed type that declares a managed pointer to a procedure, and in Clarion# it is declared in the same way that procedure type are declared in Clarion Win32.

**Conceptual Example:**

|  |
| **    PROGRAM** |
|  |
| **    NAMESPACE(MyNS),PUBLIC** |
| **    USING(System)** |
| **    USING(System.Collections)** |
|  |
| ** MAP** |
| **   MyDelegate(Object sender, EventArgs e),****DELEGATE****,PUBLIC     !Delegate declaration** |
| ** END** |
|  |
| **MyClass CLASS,TYPE** |
| **CONSTRUCT PROCEDURE(),PUBLIC** |
| **MyEvent   ****EVENT****,MyDelegate,PUBLIC                         !Event declaration of type MyDelegate** |
| **OnMyEvent PROCEDURE(Object sender, EventArgs e),PUBLIC    !EventHandler procedure with the same prototype of the declared delegate MyDelegate** |
| **        END** |
|  |
| ** CODE** |
|  |
| **MyClass.CONSTRUCT PROCEDURE()** |
| ** CODE** |
| **     SELF.MyEvent += SELF.OnMyEvent                        !Attach the EventHandler to the event** |
|  |
| **MyClass.OnMyEvent PROCEDURE(Object sender, EventArgs e)** |
| ** CODE** |
|  |

**See Also:** [[event class delegate event .htm|EVENT]]