给个参考:
http://expert.csdn.net/Expert/topic/1571/1571195.xml?temp=.9026605
http://expert.csdn.net/Expert/topic/1935/1935245.xml?temp=.3420679
http://expert.csdn.net/Expert/topic/1571/1571195.xml?temp=.9026605
http://expert.csdn.net/Expert/topic/1935/1935245.xml?temp=.3420679
不行呀大侠