The 23 Gang of Four Design Patterns (Cheat Sheet)
ref:http://social.msdn.microsoft.com/Forums/en-US/architecturegeneral/thread/af062e83-3e61-45d4-aeaa-d30b4366c6a2/1.Strategy:Definesafamilyofalgorithms,encapsulateseachone,andmaketheminterchangeable.S