看这里，

http://www.asp.net/web-api/overview/advanced/从网络客户端调用网络应用程序 [ ^ ]

http://www.c-sharpcorner.com/UploadFile/dacca2/http-request-methods-get-post- put-and-delete / [ ^ ]

http://johnnycode.com/2012/02/23/consuming-your-own-asp-net-web-api-rest-service/ [ ^ ]

HttpClient将Json数据发布到WebService [ ^ ]



-KR

试试这些链接 -

使用HttpClient调用ASP.NET WebAPI [ ^ ]

从.NET调用Web API ASP.NET Web API 2（C＃）中的客户端 [ ^ ]

使用HttpClient来使用ASP.NET Web API REST服务 [ ^ ]

How can I use http client to send json request?

Look here,
http://www.asp.net/web-api/overview/advanced/calling-a-web-api-from-a-net-client[^]
http://www.c-sharpcorner.com/UploadFile/dacca2/http-request-methods-get-post-put-and-delete/[^]
http://johnnycode.com/2012/02/23/consuming-your-own-asp-net-web-api-rest-service/[^]
HttpClient to post Json data to WebService[^]

-KR

Try these links -
Calling ASP.NET WebAPI using HttpClient[^]
Calling a Web API From a .NET Client in ASP.NET Web API 2 (C#)[^]
Using HttpClient to Consume ASP.NET Web API REST Services[^]