| Author: Legend 29 Aug 2008 | Member Level: Silver | Rating:  Points: 6 |
A delegate declaration defines a reference type that can be used to encapsulate a method with a specific signature. A delegate instance encapsulates a static or an instance method. Delegates are roughly similar to function pointers in C++; however, delegates are type-safe and secure.
This declaration takes the following form::
attributes (Optional)
Additional declarative information. For more information on attributes and attribute classes, see 17. Attributes.
modifiers (Optional)
The allowed modifiers are new and the four access modifiers.
result-type
The result type, which matches the return type of the method.
identifier
The delegate name.
formal-parameters (Optional)
Parameter list. If a parameter is a pointer, the delegate must be declared with the unsafe modifier.
Example 1
// keyword_delegate.cs
// delegate declaration
delegate void MyDelegate(int i);
class Program
{
public static void Main()
{
TakesADelegate(new MyDelegate(DelegateFunction));
}
public static void TakesADelegate(MyDelegate SomeFunction)
{
SomeFunction(21);
}
public static void DelegateFunction(int i)
{
System.Console.WriteLine("Called by delegate with number: {0}.", i);
}
}
Output
Called by delegate with number: 21.
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| Author: Athira Appukuttan 29 Aug 2008 | Member Level: Diamond | Rating: Points: 6 |
Hi..
Delegates add a safety to the idea of traditional function pointers. The .NET framework has added the bonus of providing a type-safe mechanism called delegates. They follow a Trust-But-Verify model, with automatic verification of the signature by the compiler. Unlike function pointers however, delegates are object-oriented, type-safe, and secured. In short, a delegate is a data structure that refers to a static method or to an object instance, and an instance method of that object. When the delegate references an instance method, it stores not only a reference to the method entry point, but also a reference to the object instance for which to invoke the method.
For more..
http://www.codeproject.com/KB/vb/Delegate.aspxhttp://www.aspnettutorials.com/tutorials/advanced/delegate-aspnet2-csharp.aspx
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