C#によるシンプルなイクステンション作成
[http://www.codeproject.com/useritems/ExtensionFramework.asp:title=A Simple Extension Framework in C# - The Code Project - C# Programming
]
[http://www.codeproject.com/useritems/ExtensionFramework.asp:title=A Simple Extension Framework in C# - The Code Project - C# Programming
]