c#与webapi交互

 public static string HttpConnectToServer(string ServerPage,string strData)
     {
         string postData =strData;
         //解决乱码问题
         byte[] dataArray = Encoding.UTF8.GetBytes(postData);
         //创建请求
         HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(ServerPage);
         request.Method = "POST";
         request.ContentLength = dataArray.Length;
         request.ContentType = "application/json;charset=UTF-8";
         //创建输入流
         Stream dataStream = null;
         try
         {
             dataStream = request.GetRequestStream();
         }
         catch (Exception)
         {
             return null;//连接服务器失败
         }

         //发送请求
         dataStream.Write(dataArray, , dataArray.Length);
         dataStream.Close();
         //读取返回消息
         string res = string.Empty;
         try
         {
             HttpWebResponse response = (HttpWebResponse)request.GetResponse();
             StreamReader reader = new StreamReader(response.GetResponseStream(), Encoding.UTF8);
             res = reader.ReadToEnd();
             reader.Close();
         }
         catch (Exception ex)
         {
             return null;//连接服务器失败
         }
         return res;
     }