两篇博客:
1111------------http://www.cnblogs.com/dolphin0520/archive/2011/09/17/2179466.html
2222-------------http://blog.csdn.net/sno_guo/article/details/8042332
两篇博客:
1111------------http://www.cnblogs.com/dolphin0520/archive/2011/09/17/2179466.html
2222-------------http://blog.csdn.net/sno_guo/article/details/8042332