我正在尝试使用参数调用Web服务（asmx），但始终收到“缺少参数：Lane”响应。下面的代码是我正在使用的

final HttpClient Client = new DefaultHttpClient();
        String jsonstring = "",step = "0";
        try { 
            List<NameValuePair> params = new ArrayList<NameValuePair>();
            params.add(new BasicNameValuePair("Lane","1"));
            params.add(new BasicNameValuePair("Name","Test test")); 

            HttpPost httppostreq = new HttpPost(url);  

            httppostreq.setEntity(new UrlEncodedFormEntity(params));

            HttpResponse httpresponse = Client.execute(httppostreq);

            jsonstring = EntityUtils.toString(httpresponse.getEntity());

当我在标题中添加参数并设置“内容类型：application / x-www-form-urlencoded”时，我可以使用邮递员来调用Web服务，但不能使其在Android Studio中工作

这是我的网络服务中的代码：

   [WebMethod]
    public void MyTestService(string Lane,string Name)
    {
            Dictionary<string,object> parameter = new Dictionary<string,object>();
            parameter.Add("@lane",Lane);
            parameter.Add("@name",Name);

            DataSet dt = Dataaccess.executeStoreProcedureDataSet("sp_GetLaneName",parameter);
            string jsonReturned = JsonConvert.SerializeObject(dt,Formatting.Indented);
            Context.response.contenttype = "text/plain; charset=UTF-8";
            Context.Response.Write(jsonReturned);           
    }