C# 上载文件时，ASP.NET web服务引发System.NET.WebException

我在asp.net中有一个web服务，需要将文件上载到另一台服务器。在VisualStudio中以调试模式播放时，代码运行良好。但当我在IIS中托管并调用它时，它会抛出System.Net.WebException。这是我的密码：

    [WebMethod]
    public string UploadFileToServer(string m_fileName, string m_username, string m_url)
    {
        string m_localFilePath = _currentDirectory + "\\" + m_username + "\\" + m_fileName;
        FileStream m_localFileStream = File.Open(m_localFilePath, FileMode.Open, FileAccess.Read);
        var reader = new BinaryReader(m_localFileStream);

        byte[] m_rawBytes = new byte[m_localFileStream.Length];
        reader.Read(m_rawBytes, 0, m_rawBytes.Length);
        try
        {
            HttpWebRequest request = (HttpWebRequest)WebRequest.Create(m_url);
            request.Method = "POST";
            request.KeepAlive = false;

            Stream m_requestStream = request.GetRequestStream();
            m_requestStream.Write(m_rawBytes, 0, m_rawBytes.Length);
            m_requestStream.Close();
            m_localFileStream.Close();

            HttpWebResponse m_response = (HttpWebResponse)request.GetResponse();
            StreamReader m_reader = new StreamReader(m_response.GetResponseStream());

            string s = m_reader.ReadToEnd();

            return s;
        }
        catch (Exception ex)
        {
            return ex.ToString() + ex.Message;
        }
    }

---

这对我来说非常沮丧，不可能一直打开我的VisualStudio。有什么建议或解决办法吗？谢谢。

WebException的消息和堆栈跟踪是什么？当您“在visual studio中以调试模式播放”时，您的本地计算机上是否有所有内容（要上载的文件、正在调用的Web服务）？当您部署并运行Web服务时，您是否试图打开指定目录中不存在的文件？