您之前也发布了相同的问题..

http://www.codeproject.com/Answers/255284/what-is- the-returnurl-mean#answer1 [ ^ ]

该帖子中提供了解决方案...您不了解的是什么...

You posted the same question earlier too..

http://www.codeproject.com/Answers/255284/what-is-the-returnurl-mean#answer1[^]

The solution was provided in that post...what is it that you don''t understand...