c# - 将文件从 FTP 下载到客户端 PC

Question

在我的应用程序中，我有一个要求，客户端/用户需要将视频文件从 ftp 服务器下载到他们的本地机器。

通过使用下面的代码，我可以从 ftp 下载文件，但它只保存在我的应用程序服务器上，而不是本地客户端 PC。我想将文件下载到客户端电脑，它应该在下载前询问对话框。

我的代码如下，

        string ResponseDescription = "";
        string PureFileName = new FileInfo(filename).Name;
        string DownloadedFilePath = @"E:\\aa\\" + PureFileName;
        String downloadUrl = String.Format("{0}/{1}", "ftp://abcd.int/", filename);
        FtpWebRequest req = (FtpWebRequest)FtpWebRequest.Create(downloadUrl);
        req.Method = WebRequestMethods.Ftp.DownloadFile;
        req.Credentials = new NetworkCredential("username", "password");
        req.UseBinary = true;
        req.Proxy = null;
            FtpWebResponse response = (FtpWebResponse)req.GetResponse();
            Stream stream = response.GetResponseStream();
            byte[] buffer = new byte[2048];
            FileStream fs = new FileStream(DownloadedFilePath, FileMode.Create);
            int ReadCount = stream.Read(buffer, 0, buffer.Length);
            while (ReadCount > 0)
            {
                fs.Write(buffer, 0, ReadCount);
                ReadCount = stream.Read(buffer, 0, buffer.Length);
            }
            ResponseDescription = response.StatusDescription;
            fs.Close();
            stream.Close();