http://www.docin.com/p-647062205.html
http://blog.csdn.net/luyee2010/article/category/1285622
http://www.cnblogs.com/gpcuster/archive/2011/04/12/2013411.html
http://wenku.baidu.com/link?url=Rj8K3X-Qa-E5dRbdcii_9nLFUVkz_7FxATKxc6bVx2sSWNn_AI26psCBiFe4UoiTaZT_OSyBUpT697wprBhEXLzg31RUTYqkbLCdPyYnX2i
http://blog.csdn.net/iAm333/article/details/38538073