WebView2 下载进度

Question

需要通过 WebView2 获取下载进度。 https://docs.microsoft.com/en-us/dotnet/api/microsoft.web.webview2.core.corewebview2downloadoperation?view=webview2-dotnet-1.0.865-prerelease

async void InitializeAsync()
{
  var env = await CoreWebView2Environment.CreateAsync(Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData) + @"\Microsoft\EdgeCore\92.0.887.0");
  await webView.EnsureCoreWebView2Async(env);
  webView.CoreWebView2.DownloadStarting += webView_DownloadStarting;
  webView.CoreWebView2.Navigate("downloadURL");
}

private void webView_DownloadStarting(object sender, CoreWebView2DownloadStartingEventArgs e)
{           
  e.ResultFilePath = filename;
  public event EventHandler<object> BytesReceivedChanged; <-- Need this event for print bytes to webView_BytesReceivedChanged
  public event EventHandler<object> StateChanged; <-- Need this event for print download state to webView_StateChanged
}

private void webView_BytesReceivedChanged(object sender, CoreWebView2DownloadStartingEventArgs e)
{
  Console.WriteLine(e.DownloadOperation.BytesReceived); // Bytes received
  Console.WriteLine(e.DownloadOperation.TotalBytesToReceive); // Total bytes to receive
}

private void webView_StateChanged(object sender, CoreWebView2DownloadStartingEventArgs e)
{
  Console.WriteLine(e.DownloadOperation.State); //2 Completed, 1 In progress, 0 Error
}

我试过了：

public event EventHandler BytesReceivedChanged;
BytesReceivedChanged += webView_BytesReceivedChanged;

但事件从未触发

Answer 1

注意（对于阅读本文的其他人）：这需要版本“1.0.865-prerelease”或更高版本。首先订阅CoreWebView2.DownloadStartingevent。您可以在CoreWebView2InitializationCompletedeventhandler 中执行此操作，或如上所示。

现在在CoreWebView2.DownloadStarting 事件处理程序中保存对CoreWebView2DownloadOperation 的引用并订阅BytesReceivedChanged 和EstimatedEndTimeChanged。

这是代码（假设您的 WebView2 被称为“webView21”）：

using Microsoft.Web.WebView2.Core;

CoreWebView2DownloadOperation downloadOperation;

private void WebView21_CoreWebView2InitializationCompleted(object sender, CoreWebView2InitializationCompletedEventArgs e)
{
    webView21.CoreWebView2.DownloadStarting += CoreWebView2_DownloadStarting;
}

private void CoreWebView2_DownloadStarting(object sender, CoreWebView2DownloadStartingEventArgs e)
{
    downloadOperation = e.DownloadOperation; // Store the 'DownloadOperation' for later use in events
    downloadOperation.BytesReceivedChanged += DownloadOperation_BytesReceivedChanged; // Subscribe to BytesReceivedChanged event
    downloadOperation.EstimatedEndTimeChanged += DownloadOperation_EstimatedEndTimeChanged; // Subsribe to EstimatedEndTimeChanged event
}

private void DownloadOperation_EstimatedEndTimeChanged(object sender, object e)
{
    label1.Text = downloadOperation.EstimatedEndTime.ToString(); // Show the progress
}

private void DownloadOperation_BytesReceivedChanged(object sender, object e)
{
    label2.Text = downloadOperation.BytesReceived.ToString(); // Show the progress
}

现在标签将显示进度。