C#使用Http Post方式传递Json数据字符串调用Web Service

[WebMethod]    public string Project(string paramaters)    {      return paramaters;    }

public string Post(string methodName, string jsonParas)    {      string strURL = Url + "/" + methodName;      //创建一个HTTP请求       HttpWebRequest request = (HttpWebRequest)WebRequest.Create(strURL);      //Post请求方式       request.Method = "POST";      //内容类型      request.ContentType = "application/x-www-form-urlencoded";      //设置参数，并进行URL编码       //虽然我们需要传递给服务器端的实际参数是JsonParas(格式：[{/"UserID/":/"0206001/",/"UserName/":/"ceshi/"}])，      //但是需要将该字符串参数构造成键值对的形式（注："paramaters=[{/"UserID/":/"0206001/",/"UserName/":/"ceshi/"}]"），      //其中键paramaters为WebService接口函数的参数名，值为经过序列化的Json数据字符串      //最后将字符串参数进行Url编码      string paraUrlCoded = System.Web.HttpUtility.UrlEncode("paramaters");      paraUrlCoded += "=" + System.Web.HttpUtility.UrlEncode(jsonParas);      byte[] payload;      //将Json字符串转化为字节       payload = System.Text.Encoding.UTF8.GetBytes(paraUrlCoded);      //设置请求的ContentLength        request.ContentLength = payload.Length;      //发送请求，获得请求流       Stream writer;      try      {        writer = request.GetRequestStream();//获取用于写入请求数据的Stream对象      }      catch (Exception)      {        writer = null;        Console.Write("连接服务器失败!");      }      //将请求参数写入流      writer.Write(payload, 0, payload.Length);      writer.Close();//关闭请求流      String strValue = "";//strValue为http响应所返回的字符流      HttpWebResponse response;      try      {        //获得响应流        response = (HttpWebResponse)request.GetResponse();      }      catch (WebException ex)      {        response = ex.Response as HttpWebResponse;      }      Stream s = response.GetResponseStream();      //服务器端返回的是一个XML格式的字符串，XML的Content才是我们所需要的Json数据      XmlTextReader Reader = new XmlTextReader(s);      Reader.MoveToContent();      strValue = Reader.ReadInnerXml();//取出Content中的Json数据      Reader.Close();      s.Close();      return strValue;//返回Json数据    }