C # Extension Methods

In C #, extension methods enable you to add methods to existing class without creating a new derived class.

Extension Methods Requirements:

1. Define a static class to contain extension method. This class must is visible to client code.
2. Implement the extension method like a static method, but add "this" modifier before the first parameter.
3. The first parameter specifies the type, this extension method operates on.

1 usingSystem.Globalization;2 usingSystem.Threading;3 4 namespaceLibrary5 {6      Public Static classstringextensions7     {8         //static Method9         //Public static String Converttotitlecase (this string source)Ten         //extension Method One          Public Static stringConverttotitlecase ( This stringsource) A         { -CultureInfo CultureInfo =Thread.CurrentThread.CurrentCulture; -TextInfo TextInfo =Cultureinfo.textinfo; the  -             returntextinfo.totitlecase (source); -         } -     } +}

Extension Methods Call:

Call extension method, like extension method, is a instance method on the type.

1 namespaceLibrary_simple2 {3     //Import extension Method namespace4     usingLibrary;5     class Program6     {7         Static voidMain (string[] args)8         {9             stringSource ="The return of the king";Ten             stringextected ="The Return of the King"; One  A             //static Method -             //string result = Stringextensions.converttotitlecase (source); -             //extension Method the             stringresult =source. Converttotitlecase (); -  - assert.isnotnull (result); - assert.areequal (expected, result); +         } -     } +}

C # Extension Methods