C#使用HttpPost请求调用WebService的方法

public class WebServiceDemo : System.Web.Services.WebService {  [WebMethod]  public string HelloWorld()  {   return "Hello World";  }  [WebMethod]  public string Sum(string param1, string param2)  {   int num1 = Convert.ToInt32(param1);   int num2 = Convert.ToInt32(param2);   int sum = num1 + num2;   return sum.ToString();  } }

class Program {  static void Main(string[] args)  {   Program program = new Program();   string url = "http://localhost:12544/WebServiceDemo.asmx";   string method = "Sum";   string num1 = "1";   string num2 = "2";   string result = program.HttpPostWebService(url, method, num1, num2);   Console.WriteLine(result);   Console.ReadKey();  }  public string HttpPostWebService(string url,string method,string num1,string num2)  {   string result = string.Empty;   string param = string.Empty;   byte[] bytes = null;   Stream writer = null;   HttpWebRequest request = null;   HttpWebResponse response = null;   param = HttpUtility.UrlEncode("param1") + "=" + HttpUtility.UrlEncode(num1) + "&" + HttpUtility.UrlEncode("param2") + "=" + HttpUtility.UrlEncode(num2);   bytes = Encoding.UTF8.GetBytes(param);   request = (HttpWebRequest)WebRequest.Create(url + "/" + method);   request.Method = "POST";   request.ContentType = "application/x-www-form-urlencoded";   request.ContentLength = bytes.Length;   try   {    writer = request.GetRequestStream();  //获取用于写入请求数据的Stream对象   }   catch (Exception ex)   {    return "";   }   writer.Write(bytes, 0, bytes.Length);  //把参数数据写入请求数据流   writer.Close();   try   {    response = (HttpWebResponse)request.GetResponse();  //获得响应   }   catch (WebException ex)   {    return "";   }   #region 这种方式读取到的是一个返回的结果字符串   Stream stream = response.GetResponseStream();  //获取响应流   XmlTextReader Reader = new XmlTextReader(stream);   Reader.MoveToContent();   result = Reader.ReadInnerXml();   #endregion   #region 这种方式读取到的是一个Xml格式的字符串   //StreamReader reader = new StreamReader(response.GetResponseStream(), Encoding.UTF8);   //result = reader.ReadToEnd();   #endregion   response.Dispose();   response.Close();   //reader.Close();   //reader.Dispose();   Reader.Dispose();   Reader.Close();   stream.Dispose();   stream.Close();   return result;  } }

<system.web> <webServices>  <protocols>  <add name="HttpPost" />  </protocols> </webServices> </system.web>