小弟我快疯了，关于wp http post 的有关问题

我快疯了，关于wp http post 的问题
不管我做任何的处理或者不处理， 当调用 
request.BeginGetResponse(new AsyncCallback(GetResponseCallback), data);
线程就阻塞了，永远也没用办法触发 GetResponseCallback，即使我随便填了一个url，一般来说就算http请求时错误的，那也总得有个结果吧，代码；

        private ResultData HttpPost(MemoryStream stream)
        {
            try
            {
                stream.Position = 0;
                trace = Trace(stream);
                HttpWebRequest request = WebRequest.CreateHttp(ConfigurationManager.BaseUrl);
                request.ContentType = "application/json";
                request.Method = "POST";
                request.ContentLength = stream.Length;

                AsyncRequestData data = new AsyncRequestData()
                {
                    Request = request,
                    Data = stream
                };
                request.BeginGetRequestStream(new AsyncCallback(GetRequestStreamCallback), data);
                _PostDoned.WaitOne();

                return Result;
            }
            catch (Exception ex)
            {
                throw new Exception("请求出错");
            }
        }
        private void GetRequestStreamCallback(IAsyncResult asyncResult)
        {
            try
            {
                AsyncRequestData asyncData = asyncResult.AsyncState as AsyncRequestData;
                HttpWebRequest request = asyncData.Request;
                MemoryStream mStream = asyncData.Data as MemoryStream;

                Stream httpStream = request.EndGetRequestStream(asyncResult);