记录下找到的链接，方便之后查看与学习。
http://www.cnblogs.com/v-July-v/archive/2011/02/14/1983678.html
https://www.zhihu.com/question/19927564
http://developer.51cto.com/art/201105/262159.htm
http://www.cnblogs.com/morewindows/category/314533.html
