1、传多个参数
接口定义：（ResponseFormat与RequestFormat分别将相应参数序列化、请求参数反序列化）
[OperationContract]
[WebInvoke(UriTemplate = “api/fun2”, Method = “POST”, BodyStyle = WebMessageBodyStyle.Wrapped, ResponseFormat = WebMessageFormat.Json, RequestFormat = WebMessageFormat.Json)]
string TestFun2(string p1,string p2);
实现：
public string TestFun2(string p1, string p2)
{
return p1+p2;
}
调用：

private void button1_Click(object sender, EventArgs e)
{
   try
   {
      string sUrl3 = "http://localhost:10086/api/fun2";
      string sBody2 = JsonConvert.SerializeObject(new { p1 = "1", p2 = "2" });
      HttpHelper.HttpPost(sUrl3, sBody2);
   }
   catch (Exception ex)
   {}
}

HttpHelper.cs

/// <summary>
/// HttpPost (application/json)
/// </summary>
/// <param name="url"></param>
/// <param name="body"></param>
/// <param name="contentType"></param>
/// <returns></returns>
public static string HttpPost(string url, string body)
{
    string responseContent = string.Empty;
    HttpWebRequest httpWebRequest = (HttpWebRequest)WebRequest.Create(url);
    httpWebRequest.ContentType = "application/json";
    httpWebRequest.Method = "POST";
    httpWebRequest.Timeout = 200000000;
    //httpWebRequest.KeepAlive = true;
    httpWebRequest.MaximumResponseHeadersLength = 40000;
    byte[] btBodys = Encoding.UTF8.GetBytes(body);
    httpWebRequest.ContentLength = btBodys.Length;
    using (Stream writeStream = httpWebRequest.GetRequestStream())
    {
        writeStream.Write(btBodys, 0, btBodys.Length);
    }
    using (HttpWebResponse httpWebResponse = (HttpWebResponse)httpWebRequest.GetResponse())
    {
        using (StreamReader streamReader = new StreamReader(httpWebResponse.GetResponseStream()))
        {
            responseContent = streamReader.ReadToEnd();
        }
    }
    return responseContent;
}

2、传对象
接口定义：
[OperationContract]
[WebInvoke(UriTemplate = “api/fun”, ResponseFormat = WebMessageFormat.Json, RequestFormat = WebMessageFormat.Json, Method = “POST”, BodyStyle = WebMessageBodyStyle.Bare)]
string TestFun(TestModel data);

public string TestFun(TestModel pars)
 {
    try
    {
       return pars.Test1 + pars.Test2;
    }
    catch (Exception ex)
    {}
}

调用：

private void button1_Click(object sender, EventArgs e)
{
   try
   {
      string sUrl = "http://localhost:10086/api/fun";
      TestModel model = new TestModel();
      model.Test1 = "1";
      model.Test2 = "2";
      string sBody = JsonConvert.SerializeObject(model);
      HttpHelper.HttpPost(sUrl, sBody);
   }
   catch (Exception ex)
   { }
}