c# - C#DownloadFileTaskAsync 不下载嵌套的 zip 文件

Question

请帮助 C# 新手，

我正在尝试使用 SSIS 中的脚本任务从 HTTPS 站点下载压缩文件。每个“外部”压缩文件都包含“内部”压缩文件，其中包含 3 个 txt 文件。

经过广泛的搜索，我用“await”、“.Wait()”甚至“while (webClient.IsBusy)”增强了 DownloadFileTaskAsync，但仍然设法只下载空的“外部”zip 文件。

请帮助我找到一种方法来下载完整的“外部”文件，该文件不会为空，但会包含“内部”zip 和其中的所有 3 个 txt 文件：

    public async void Main()
    {
        WebClient webClient = new WebClient();
        webClient.Credentials = new NetworkCredential("myuser", "password", "https://example.com/Login.htm");

        webClient.DownloadFileTaskAsync(new Uri("https://example.com/#/FROMsender/EXTERNAL_20160706.zip"), @"C:\temp\Test\EXTERNAL_20160706.zip").Wait();
        while (webClient.IsBusy) Thread.Sleep(1000);

        Dts.TaskResult = (int)ScriptResults.Success;
    }

>

Answer 1

试试这个，给 webClient 添加一些头文件：

public async void Main()
{
    WebClientEx webClient = new WebClientEx();  // <= use WebClientEx
    webClient.Credentials = new NetworkCredential("myuser", "password", "https://example.com/Login.htm");

    // Add headers here ------------
    webClient.Headers.Add("User-Agent", "Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/51.0.2704.79 Safari/537.36");
    webClient.Headers.Add("Accept", "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8");
    webClient.Headers.Add("Accept-Language", "en-US,en;q=0.5");
    webClient.Headers.Add("Accept-Encoding", "gzip, deflate");
    webClient.Headers.Add("Cache-Control", "max-age=0");
    webClient.Headers.Add("DNT", "1");
    //------------------------------

    webClient.DownloadFileTaskAsync(new Uri("https://example.com/#/FROMsender/EXTERNAL_20160706.zip"), @"C:\temp\Test\EXTERNAL_20160706.zip").Wait();
    while (webClient.IsBusy) Thread.Sleep(1000);

    Dts.TaskResult = (int)ScriptResults.Success;
}

并使用此类而不是 WebClient：

public class WebClientEx : WebClient
{
    protected override WebRequest GetWebRequest(Uri address)
    {
      var webRequest = (HttpWebRequest) base.GetWebRequest(address);
      if (webRequest != null)
      {
        webRequest.AutomaticDecompression = DecompressionMethods.GZip | DecompressionMethods.Deflate;
      }
      return webRequest;
    }
}