c# - 从服务器下载文件(不下载？)

Question

我目前正在开发一个客户端，需要一个按钮来检查目录以查看其中是否存在特定文件夹，如果不存在，它将从我的网络服务器下载 .zip 文件，下载完成后，提取说.zip 文件复制到目录。

由于某种原因，应用程序返回它已完成，但它根本没有下载任何内容。我使用了在网上找到的教程来执行此操作 ( http://www.ultimateprogrammingtutorials.info/2013/06/how-to-make-downloader-in-c.html )，并进行了一些修改。

这是我的下载代码:

下载按钮:

private void btnDownload_Click(object sender, EventArgs e)
    {
        if (!Directory.Exists(HardCorpsPath))
        {
            //MessageBox.Show("Downloading HardCorps Mod Pack (Full)", "Downloading", MessageBoxButtons.OK, MessageBoxIcon.Information);
            zipFileName = "HardCorps";

            HCDownloadURL = String.Format("http://www.survivaloperations.net/client/hardcorps/{0}.zip", zipFileName);

            WebClient Download_Client = new WebClient();//Declaring the webclient as Download_Client
            Download_Client.DownloadFileCompleted += new AsyncCompletedEventHandler(Completed);//the event handler
            Download_Client.DownloadProgressChanged += new DownloadProgressChangedEventHandler(ProgressChanged);// " "
            Download_Client.DownloadFileAsync(new Uri(HCDownloadURL.Trim().ToString()), Arma2OAPath);// " "

            //extract zip
            HCZipPath = Path.Combine(Arma2OAPath, @"HardCorps.zip");

            using (var zipFile = ZipFile.Read(HCZipPath))
            {
                zipFile.ExtractAll(Arma2OAPath, ExtractExistingFileAction.OverwriteSilently);
            }


        }
        else
        {
            MessageBox.Show("Directory Validated!");
            //Read users HardCorpsPath\version.txt and compare to server version.txt
            //if server version > user version, download patch.zip where "patch" == the number version of the server's version.txt (ex: 1001.zip)
            //On download complete, extract to HardCorpsPath and overwrite silently
        }
    }//close Download Button

其余:

private void ProgressChanged(object sender, DownloadProgressChangedEventArgs e)
    {
        pbDownloader.Value = e.ProgressPercentage;//setting the progressbar value as downloadprogress
    }
    private void Completed(object sender, AsyncCompletedEventArgs e)
    {
        MessageBox.Show("Downloading Successful ", "Download_Completed", MessageBoxButtons.OK, MessageBoxIcon.Information);//just a messagebox          
        pbDownloader.Value = (0);//resetting the progressbar
    }

在应用程序尝试解压缩不存在的文件之前，我不会收到任何错误。

非常迷失和困惑，可以用一双新的眼睛来发现问题。

谢谢!

Answer 1

您的问题可能是您在应该传递文件名时将文件路径传递给 DownloadFileAsync。

string fullFileName = Arma2OAPath + "test.zip";
Download_Client.DownloadFileAsync(new Uri(HCDownloadURL.Trim().ToString()), fullFileName );

另一个问题是 DownloadFileAsync是非阻塞的。这意味着您可以立即开始解压缩文件，而无需等待文件下载。您应该将解压缩移至 Completed()。