Question

我做了@Enigmativity写的这是：

        Action<int, ProgressBar, Label, Label, int, Button> downloadFileAsync = (i, pb, label2, label1, ServID, button1) =>
    {
        var bd = AppDomain.CurrentDomain.BaseDirectory;
        var fn = bd + "/" + i + ".7z";
        var down = new WebClient();
        DownloadProgressChangedEventHandler dpc = (s, e) =>
        {
            label1.Text = "Download Update: " + i + " From: " + ServID;
            int rec =Convert.ToInt16(e.BytesReceived / 1024);
            int total =Convert.ToInt16(e.TotalBytesToReceive / 1024)  ;
            label2.Text = "Downloaded: " + rec.ToString() + " / " + total.ToString() + " KB";
            pb.Value = e.ProgressPercentage;
        };
        AsyncCompletedEventHandler dfc = null;  dfc = (s, e) =>
        {
            down.DownloadProgressChanged -= dpc;
            down.DownloadFileCompleted -= dfc;
            CompressionEngine.Current.Decoder.DecodeIntoDirectory(AppDomain.CurrentDomain.BaseDirectory + "/" + i + ".7z", AppDomain.CurrentDomain.BaseDirectory);
            File.Delete(fn);
               if (i == ServID)
                {

                   button1.Enabled = true;
                   label1.Text = "Game Is Up-To-Date.Have Fun!!";
                  label2.Text = "Done..";
               }
         down.Dispose();
        };

我现在唯一的问题是当程序提取下载的文件时

CompressionEngine.Current.Decoder.DecodeIntoDirectory(AppDomain.CurrentDomain.BaseDirectory + "/" + i + ".7z", AppDomain.CurrentDomain.BaseDirectory);

在某些文件中，需要时间来取消下载的文件那么我怎么能告诉程序要等到解压缩完成呢？

Answer 1

尝试定义一个将封装单个异步下载的lambda，然后在循环中调用它。

这是lambda：

Action<int> downloadFileAsync = i =>
{
    var bd = AppDomain.CurrentDomain.BaseDirectory;
    var fn = bd + "/" + i + ".7z";
    var wc = new WebClient();
    DownloadProgressChangedEventHandler dpc = (s, e) =>
    {
        progressBar1.Value = e.ProgressPercentage;
    };
    AsyncCompletedEventHandler dfc = null;
    dfc = (s, e) =>
    {
        wc.DownloadProgressChanged -= dpc;
        wc.DownloadFileCompleted -= dfc;
        CompressionEngine.Current.Decoder.DecodeIntoDirectory(fn, bd);
        File.Delete(fn);
        wc.Dispose();
    };
    wc.DownloadProgressChanged += dpc;
    wc.DownloadFileCompleted += dfc;
    wc.DownloadFileAsync(new Uri(Dlpath + i + "/" + i + ".7z"), fn);
};

您会注意到它很好地分离了所有事件并正确处理了WebClient实例。

现在这样称呼：

while (i <= ServID)
{
    downloadFileAsync(i);
    i++;
}

您必须调整进度条更新以正确显示所有文件下载的进度，但原则上这应该适合您。

WebClient不支持并发I / O操作

1 个答案: