C # Study Notes (2)

C #3.0 new feature Extension Method

The extension method allows you to write and declare associated classes outside of its class.

It is used when no source code or a class is sealed and a new method needs to be added to the class.

1. The extension method must be declared as static.
2. The class of the extension method declaration must be declared as static.
3. The extension method must contain the keyword "this" as its first parameter type.

Example:

Static class ExtendMyData

{

Public static double average (this MyData md)

{

......

}

}

 

The method for calling an extension method is the same as that for calling a method in this class. The class name is added with the dot symbol and the method name.