webview2 flicking

[vzhilong]

My microsoft edge webview2 runtime upgrade to 129.0.2792.52, and when create the webview2 instance there may be a white window flicking and close quickly.

The problem reproduction easily, just open the winui3 gallery app and switch to the webview2 demo page.

Here are my reproduction captures bellow:

[vzhilong]

[Zulu-Inuoe]

We are seeing this same issue. There is a sample project https://github.com/stegru/webview-poc which demonstrates the issue

[stegru]

[michael-hawker]

I can also verify that I saw this in the WinUI Gallery app 2.4.3 on 23H2 22631.4169 when switching to the WebView2 page, there's a briefest flash of a window.

[andresledo]

I have the same issue, every time it starts it opens a window and closes in milliseconds.

[NikolaiKobzev]

I've encountered this issue in my project as well, and I also saw it reproduced in the WinUI 3 Gallery.
This window flickers for each WebView2 instance opened in the project.

[stegru]

Minimal code required:

WebView2 webView2 = new WebView2();
webView2.EnsureCoreWebView2Async();

webView2.EnsureCoreWebView2Async().AsTask().Wait(); will let the phantom window remain (due to the expected deadlock).

[RuddyOne]

Also having this issue while using MAUI, there is also an issue over there for this.

dotnet/maui#24933

[ITaluone]

Can verify too

[NicholasChrzan]

Here is the issue on Webview2 GitHub:
MicrosoftEdge/WebView2Feedback#4834

Looks like it affects more than just WinUI and is at its root a WebView2 issue.

[vzhilong]

Here is the issue on Webview2 GitHub: MicrosoftEdge/WebView2Feedback#4834

Looks like it affects more than just WinUI and is at its root a WebView2 issue.

It seems to be a very obvious excepiton.
I wonder if there is no qa work in MS.

[NicholasChrzan]

There was a workaround posted in the WebView2 issue:
MicrosoftEdge/WebView2Feedback#4834 (comment)

Environment.SetEnvironmentVariable("WEBVIEW2_ADDITIONAL_BROWSER_ARGUMENTS", "--window-size=0,0 --window-position=20000,20000");

[DmitriyKomin]

Thanks for linking to the Edge issue and workaround, @NicholasChrzan! It certainly looks like the WebView2Runtime issue described in MicrosoftEdge/WebView2Feedback#4834, so I'm closing this bug.