可以参考:
http://blog.csdn.net/houzengjiang/article/details/7718548 http://www.cnblogs.com/haippy/archive/2011/12/04/2276064.html
http://blog.csdn.net/houzengjiang/article/details/7718548
http://www.cnblogs.com/haippy/archive/2011/12/04/2276064.html