1：http://wenku.baidu.com/link?url=TgINzLf6MLbMkEviH-v59Ptbp1wly2D02zsTHTwviwfHQXl__-zHZrsPIU6MxToIcbC80o49D6molp2pbddmLXFYM9vITO4Gkzd8SzClhAm
2：http://blog.csdn.net/swairf/article/details/8598985
