来源:http://chenhaodejia.iteye.com/blog/1123289
http://www.cnblogs.com/lm3515/archive/2011/03/16/1985792.html
http://gqdy365.iteye.com/blog/1074076
http://blog.csdn.net/flowingflying/article/details/6304289
http://blog.csdn.net/flowingflying/article/details/6449582
问答:http://ask.csdn.net/questions/1222