参考文档：
http://blog.csdn.net/jdh99/article/details/39525451
http://blog.csdn.net/jdh99/article/details/39204129
http://blog.csdn.net/jdh99/article/details/6226435
http://www.oschina.net/code/snippet_1243295_48623
原文：http://www.cnblogs.com/ribavnu/p/4808911.html