c# - 如何在不使用“文件下载”对话框的情况下使用 WebBrowser 控件下载文件？

Question

在 WPF 项目中，我使用该方法

webBrowser.Navigate(strUrl);

从服务器获取PNG图片。

出现以下对话框：

我怎样才能无缝下载图片（没有对话框）？

标签： c#wpfwebbrowser-control

Answer 1

您不需要为此使用浏览器控件。

尝试使用DownloadFileAsync()

这是一个完整的工作示例。（根据需要更改路径。）

    private void Button_Click(object sender, RoutedEventArgs e)
    {
        WebClient client = new WebClient();
        client.DownloadFileAsync(new Uri("https://www.example.com/filepath"), @"C:\Users\currentuser\Desktop\Test.png");
        client.DownloadFileCompleted += Client_DownloadFileCompleted;
        client.DownloadProgressChanged += Client_DownloadProgressChanged;
    }

    private void Client_DownloadProgressChanged(object sender, DownloadProgressChangedEventArgs e)
    {
        progressBar.Value = e.ProgressPercentage;
        TBStatus.Text = e.ProgressPercentage + "% " + e.BytesReceived + " of " + e.TotalBytesToReceive + " received.";
    }

    private void Client_DownloadFileCompleted(object sender, System.ComponentModel.AsyncCompletedEventArgs e)
    {
        MessageBox.Show("Download Completed");
    }

您可以使用默认应用打开下载的文件，如下所示：

System.Diagnostics.Process.Start(@"C:\Users\currentuser\Desktop\Test.png");

编辑：

如果您的目标只是显示 png，则可以将其下载到流中，然后将其显示在图像控件中。

完整的工作样本。

WebClient wc = new WebClient();
MemoryStream stream = new MemoryStream(wc.DownloadData("https://www.dropbox.com/s/l3maq8j3yzciedw/App%20in%205%20minutes.PNG?raw=1"));
System.Drawing.Bitmap bmp = new System.Drawing.Bitmap(stream);
bmp.Save(stream, System.Drawing.Imaging.ImageFormat.Png);
stream.Position = 0;
BitmapImage bi = new BitmapImage();
bi.BeginInit();
bi.StreamSource = stream;
bi.EndInit();
image1.Source = bi;

这是异步版本。

private void Button_Click(object sender, RoutedEventArgs e)
{
    WebClient wc = new WebClient();
    wc.DownloadDataAsync(new Uri("https://www.dropbox.com/s/l3maq8j3yzciedw/App%20in%205%20minutes.PNG?raw=1"));
    wc.DownloadDataCompleted += Wc_DownloadDataCompleted;
}

private void Wc_DownloadDataCompleted(object sender, DownloadDataCompletedEventArgs e)
{
    MemoryStream stream = new MemoryStream((byte[])e.Result);
    System.Drawing.Bitmap bmp = new System.Drawing.Bitmap(stream);
    bmp.Save(stream, System.Drawing.Imaging.ImageFormat.Png);
    stream.Position = 0;
    BitmapImage bi = new BitmapImage();
    bi.BeginInit();
    bi.StreamSource = stream;
    bi.EndInit();
    image1.Source = bi;
}