WebClient和HttpWebRequest 上传文件

public bool UpLoadFile(string fileNamePath,string url)
        {
            string timeStamp = DateTime.Now.ToString("YYYY-MM-DD HH:mm:ss");
            string userName = "*****";
            string passWord = "*****";
            string uniqueKey = "*****";
            string userkey = Md5Helper.GetMD5String(userName + passWord + uniqueKey + timeStamp);
            _webClient.Headers.Add("userName", userName);
            _webClient.Headers.Add("channelId", "*****");
            _webClient.Headers.Add("timestamp", timeStamp);
            _webClient.Headers.Add("userKey", userkey);
            _webClient.Headers.Add("model", "getPolicyZip");
            _webClient.Headers.Add("policyConstraint", "{}");
            _webClient.Encoding = Encoding.UTF8;

            try
            {
                //使用UploadFile方法可以用下面的格式  
                byte[] responseArray = _webClient.UploadFile(url, fileNamePath);
                string msg = Encoding.GetEncoding("gb2312").GetString(responseArray);
            }
            catch (Exception er)
            {
                base.error.Ex = er;
                base.error.Message = "上传失败";
                return false;
            }
            return true;
        }

public string UpLoadFile(string filePath, string url)
        {
            string responseData = String.Empty;
            HttpWebRequest req = (HttpWebRequest)HttpWebRequest.Create(url);
            FileStream fileStream = new FileStream(filePath, FileMode.Open, FileAccess.Read);
            byte[] buffur = new byte[fileStream.Length];
            fileStream.Read(buffur, 0, (int)fileStream.Length);

            req.Method = "POST";
            req.ContentType = "application/x-www-form-urlencoded";
            req.ContentLength = fileStream.Length;

            string timeStamp = DateTime.Now.ToString("YYYY-MM-DD HH:mm:ss");
            string userName = "*****";
            string passWord = "*****";
            string uniqueKey = "*****";
            string userkey = Md5Helper.GetMD5String(userName + passWord + uniqueKey + timeStamp);
            req.Headers.Add("userName", userName);
            req.Headers.Add("channelId", "*****");
            req.Headers.Add("timestamp", timeStamp);
            req.Headers.Add("userKey", userkey);
            req.Headers.Add("model", "getPolicyZip");
            req.Headers.Add("policyConstraint", "{}");

            Stream reqStream = req.GetRequestStream();
            reqStream.Write(buffur, 0, buffur.Length);
            reqStream.Close();

            using (HttpWebResponse response = (HttpWebResponse)req.GetResponse())
            {
                using (StreamReader reader = new StreamReader(response.GetResponseStream(), Encoding.GetEncoding("GB2312")))
                {
                    responseData = reader.ReadToEnd().ToString();
                }
                return responseData;
            }
        }