http://www.baidu.com/s?ie=gb2312&bs=IT%BB%F9%B1%BE%C9%E8%CA%A9%B5%C4%B7%A2%D5%B9&sr=&z=&cl=3&f=8&wd=IT%BB%F9%B1%BE%C9%E8%CA%A9%B5%C4%B7%A2%D5%B9&ct=0这个上面说的很详细