WebView causes application to crash when navigating to a different tab (InvalidCastException)

[derekantrican]

Screen recording (the "Pip Details for ...." is the WebView control):

Here's the exception details:

System.InvalidCastException
  HResult=0x80004002
  Message=Unable to cast object of type 'Avalonia.WebView.Windows.WebViewHandler' to type 'Avalonia.Controls.Platform.INativeControlHostDestroyableControlHandle'.
  Source=Avalonia.Controls
  StackTrace:
   at Avalonia.Controls.NativeControlHost.DestroyNativeControlCore(IPlatformHandle control)
   at AvaloniaWebView.Shared.Handlers.ViewHandler.DestroyNativeControlCore(IPlatformHandle control)
   at Avalonia.Controls.NativeControlHost.DestroyNativeControl()
   at Avalonia.Controls.NativeControlHost.CheckDestruction()
   at Avalonia.Threading.DispatcherOperation.InvokeCore()
   at Avalonia.Threading.DispatcherOperation.Execute()
   at Avalonia.Threading.Dispatcher.ExecuteJob(DispatcherOperation job)
   at Avalonia.Threading.Dispatcher.ExecuteJobsCore()
   at Avalonia.Threading.Dispatcher.OnOSTimer()
   at Avalonia.Win32.Win32Platform.WndProc(IntPtr hWnd, UInt32 msg, IntPtr wParam, IntPtr lParam)
   at Avalonia.Win32.Interop.UnmanagedMethods.DispatchMessage(MSG& lpmsg)
   at Avalonia.Win32.Win32DispatcherImpl.RunLoop(CancellationToken cancellationToken)
   at Avalonia.Threading.DispatcherFrame.Run(IControlledDispatcherImpl impl)
   at Avalonia.Threading.Dispatcher.PushFrame(DispatcherFrame frame)
   at Avalonia.Threading.Dispatcher.MainLoop(CancellationToken cancellationToken)
   at Avalonia.Controls.ApplicationLifetimes.ClassicDesktopStyleApplicationLifetime.Start(String[] args)
   at Avalonia.ClassicDesktopStyleApplicationLifetimeExtensions.StartWithClassicDesktopLifetime(AppBuilder builder, String[] args, ShutdownMode shutdownMode)
   at OfficeDominoAnalyzer2.Program.Main(String[] args) in OfficeDominoAnalyzer2\Program.cs:line 17

I'm on

• Avalonia 11.0.0
• WebView.Avalonia 11.0.0
• WebView.Avalonia.Desktop 11.0.0

At the moment I don't have a min repro example but if you really need one I can work on making one.

[ChisterWu]

I will try it.

[derekantrican]

@ChisterWu Any luck reproducing this?

[derekantrican]

@ChisterWu I can reproduce with simply this:

    <TabControl>
        <TabItem Header="Main">

        </TabItem>
        <TabItem Header="Player">
            <WebView/>
        </TabItem>
    </TabControl>

Put that into a Window, start the application, click "Player" tab, then click "Main" tab.

[derekantrican]

I found a (horrible, but working) workaround for the above example (while referencing this post):

XAML:

        <Grid RowDefinitions="Auto,*">
            <TabStrip x:Name="tabStrip" SelectionChanged="TabStrip_SelectionChanged">
                <TabItem Header="Main"/>
                <TabItem Header="Player"/>
            </TabStrip>
            <WebView x:Name="webView" Grid.Row="1" IsVisible="False"/>
        </Grid>

XAML.CS:

    private void TabStrip_SelectionChanged(object sender, SelectionChangedEventArgs e)
    {
        TabStrip tabStrip = sender as TabStrip;
        if (tabStrip.SelectedItem != null)
        {
            this.FindControl<WebView>("webView").IsVisible = (tabStrip.SelectedItem as TabItem).Header as string == "Player";
        }
    }

[derekantrican]

For some reason I'm having trouble reproducing this with the sample in this repo. I changed SampleWebView\MainView.axaml to this:

<Window xmlns="https://github.com/avaloniaui"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:vm="using:SampleWebView.ViewModels"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:views="clr-namespace:SampleWebView.Views"
        mc:Ignorable="d" d:DesignWidth="800" d:DesignHeight="450"
        x:Class="SampleWebView.Views.MainWindow"
        Icon="/Assets/avalonia-logo.ico"
        Title="SampleWebView">
    <TabControl>
        <TabItem Header="Tab1"/>
        <TabItem Header="Tab2">
            <WebView x:Name="PART_WebView" Url="http://www.bilibili.com"/>
        </TabItem>
    </TabControl>
</Window>

And this is the result:

So while it doesn't crash the application, the browser doesn't show back up when the tab is navigated back to. (And I'm not sure why it doesn't crash in this test - perhaps some differences in the version of Avalonia or something)

[rabbitism]

thank for the fix

[derekantrican]

Going to assume this is closed & fixed via https://github.com/AvaloniaUI/Avalonia/pull/15029 (once this goes out with a release of Avalonia)