远程服务器返回错误: (500) 内部服务器错误。

  //Http Post数据到接收方url
         public string PostFileData(string TheURL, byte[] data)
        {
                Uri uri = new Uri(TheURL);
                string result = "";
                bool bResult = true;   
                //创建请求实例  
                HttpWebRequest request = (HttpWebRequest)WebRequest.Create(uri);
                request.CookieContainer = new CookieContainer();
                //这无论是赋post还是get，都必须用全大写，此值错一点，都会导致程序错误，因为不符合http协议 
                request.Method ="POST";
                /*
                 * 值用application/x- www-form-urlencoded则form各元素用&来分隔
                 * 而元素的值是经过了url编码
                 * 调用System.Web.HttpUtility.UrlEncode方法
                 * 就能将值进行url编码。
                 */
                request.ContentType ="application/x-www-form-urlencoded";
                request.AllowAutoRedirect = false;
                //等待超时的时间长度 
                request.Timeout = 5000;
                //设置内容的长度，长度就是要发送的整个字节数组的长度，此句必须有，长度不对就会导致错误 
                request.ContentLength = data.Length;
                request.UserAgent ="Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 5.1; Trident/4.0; Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1) ; .NET CLR 2.0.50727; .NET CLR 3.0.04506.648; .NET CLR 3.5.21022)";
                //读取一个XML文件流
                //XmlDocument xml = new XmlDocument(); 
            try
            {
                //获取与远程Web Service的联络
                Stream newStream = request.GetRequestStream();
                newStream.Write(data, 0, data.Length);
                Console.WriteLine("已经发送");
                //发送完毕流信息后关闭
                newStream.Close();
            }
            catch (Exception)
            {
                //return ex.ToString();
                bResult = false; 
            }
            //只有发送数据正常时，才读取响应 
            if (bResult)
            {
                try
                {
                    //接收方响应接收    //在这一句出错，跳到catch里边。说500内部服务器错误，有时候说操作超时。
                    HttpWebResponse response = (HttpWebResponse)request.GetResponse();
                    //接收响应
                    //StreamReader reader = new StreamReader(response.GetResponseStream());
                    Stream responseStream = response.GetResponseStream();
                    StreamReader readStream = new StreamReader(responseStream, System.Text.Encoding.UTF8);
                    //string retext = readStream.ReadToEnd().ToString();
                    //接收和读取信息.
                    result = readStream.ReadToEnd();
                    readStream.Close();
                    response.Close();
                }
                    //  //Http Post数据到接收方url
         public string PostFileData(string TheURL, byte[] data)
        {
                Uri uri = new Uri(TheURL);
                string result = "";
                bool bResult = true;   
                //创建请求实例  
                HttpWebRequest request = (HttpWebRequest)WebRequest.Create(uri);
                request.CookieContainer = new CookieContainer();
                //这无论是赋post还是get，都必须用全大写，此值错一点，都会导致程序错误，因为不符合http协议 
                request.Method ="POST";
                /*
                 * 值用application/x- www-form-urlencoded则form各元素用&来分隔
                 * 而元素的值是经过了url编码
                 * 调用System.Web.HttpUtility.UrlEncode方法
                 * 就能将值进行url编码。
                 */
                request.ContentType ="application/x-www-form-urlencoded";
                request.AllowAutoRedirect = false;
                //等待超时的时间长度 
                request.Timeout = 5000;
                //设置内容的长度，长度就是要发送的整个字节数组的长度，此句必须有，长度不对就会导致错误 
                request.ContentLength = data.Length;
                request.UserAgent ="Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 5.1; Trident/4.0; Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1) ; .NET CLR 2.0.50727; .NET CLR 3.0.04506.648; .NET CLR 3.5.21022)";
                //读取一个XML文件流
                //XmlDocument xml = new XmlDocument(); 
            try
            {
                //获取与远程Web Service的联络
                Stream newStream = request.GetRequestStream();
                newStream.Write(data, 0, data.Length);
                Console.WriteLine("已经发送");
                //发送完毕流信息后关闭
                newStream.Close();
            }
            catch (Exception)
            {
                //return ex.ToString();
                bResult = false; 
            }
            //只有发送数据正常时，才读取响应 
            if (bResult)
            {
                try
                {
                    //接收方响应接收
                    HttpWebResponse response = (HttpWebResponse)request.GetResponse();
                    //接收响应
                    //StreamReader reader = new StreamReader(response.GetResponseStream());
                    Stream responseStream = response.GetResponseStream();
                    StreamReader readStream = new StreamReader(responseStream, System.Text.Encoding.UTF8);
                    //string retext = readStream.ReadToEnd().ToString();
                    //接收和读取信息.
                    result = readStream.ReadToEnd();
                    readStream.Close();
                    response.Close();
                }
                 //远程服务器返回错误: (500) 内部服务器错误。
                catch (Exception)
                {
                    return result = "";
                }
            }
            return result = "";
        }
                catch (Exception)
                {
                    return result = "";
                }
            }
            return result = "";
        }