Request Headers:

User-Agent: Fiddler
Host: localhost:3248
Content-Type: application/json; charset=utf-8  
Content-Length: 63

要加上Content-Type: application/json; charset=utf-8，要不是JSON没效

Request Body

{"UserID":4,"UserName":"Parry","UserEmail":"Parry@cnblogs.com"}

紧记，不要写成这样：[{"UserID":4,"UserName":"Parry","UserEmail":"Parry@cnblogs.com"}]

原文：http://www.cnblogs.com/jys509/p/3550598.html