//以html post方式請求json資料

private string Post(string strURL, string auth, string contentType, string jsonParas)

        {
            var httpWebRequest = (HttpWebRequest)WebRequest.Create(strURL);
            httpWebRequest.ContentType = contentType;//application/json
            httpWebRequest.Method = "POST";
            WebHeaderCollection whc = new WebHeaderCollection();
            whc.Add(auth);//authorization:xxx
            httpWebRequest.Headers.Add(whc);


            using (var streamWriter = new StreamWriter(httpWebRequest.GetRequestStream()))
            {
                streamWriter.Write(jsonParas);
                streamWriter.Flush();
                streamWriter.Close();
            }


            var httpResponse = (HttpWebResponse)httpWebRequest.GetResponse();
            using (var streamReader = new StreamReader(httpResponse.GetResponseStream()))
            {
                return streamReader.ReadToEnd();
            }

        }

推薦一款外掛（google Advanced Rest Client），可用於測試請求/響應結果。