关于依赖注入
http://www.cnblogs.com/xingyukun/archive/2007/10/20/931331.html
http://www.cnblogs.com/leoo2sk/archive/2009/06/17/1504693.html
http://www.cnblogs.com/xingyukun/archive/2007/10/20/931331.html
http://www.cnblogs.com/leoo2sk/archive/2009/06/17/1504693.html