C # Extension methods

Extension methods are defined as static methods, but they are called through the instance method syntax. Their first argument specifies which type the method acts on, and the parameter is prefixed with the This modifier.

The extension method specifies that the class must be a static class, and all of the methods contained in it must be static methods

Resource connection: http://www.cnblogs.com/ldp615/archive/2009/08/07/1541404.html

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C # Extension methods