var client = new RestClient("http://dlj.bz/api/urlshortener");
var request = new RestRequest(Method.POST);
 request.AddHeader("content-type", "application/json");
request.AddParameter("application/json", "{\"long_url\": \"http://www.sina.com.cn\"}", ParameterType.RequestBody);
IRestResponse response = client.Execute(request);