Touchscreen not working after rapidly clicking while app startup

[Eilon]

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Issue moved from dotnet/maui#16251

• Please respond to @Letiz0.

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From @Letiz0 on Thursday, July 20, 2023 10:33:49 AM

Description

711540495645142_TbyLCh92.online-video-cutter.com.1.mp4

Just like the video shows, if I rapidly click anywhere inside the app while starting up and loading, the touchsrceen will be broken but the mouse is still working.

Steps to Reproduce

1. Create a new Maui Blazor Project
2. Deploy it on any tablet
3. Repeatly touch the screen inside the app window as quickly as you can

Link to public reproduction project repository

https://github.com/Letiz0/MauiApp1

Version with bug

7.0.49

Last version that worked well

Unknown/Other

Affected platforms

Windows

Affected platform versions

net7.0-windows10.0.19041.0

Did you find any workaround?

2023/08/01 update:
I found that if I force reload the page (e.g. NavigationManager.NavigateTo(NavigationManager.Uri, forceLoad: true)), it would be solved.

Relevant log output

No response

[Eilon]

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Issue moved from dotnet/maui#16251

• Please respond to @trivalik.

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From @trivalik on Thursday, July 20, 2023 11:34:39 AM

If the MAUI app could not be used, is the operating system still useable via touch?

[Eilon]

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Issue moved from dotnet/maui#16251

• Please respond to @Letiz0.

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From @Letiz0 on Thursday, July 20, 2023 12:12:21 PM

If the MAUI app could not be used, is the operating system still useable via touch?

I can even close the MAUI app by touching the top-right "X" icon, it seems touchscreen is only broken inside the app.

[Eilon]

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Issue moved from dotnet/maui#16251

• Please respond to @msftbot[bot].

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From @msftbot[bot] on Thursday, July 20, 2023 4:39:46 PM

We've added this issue to our backlog, and we will work to address it as time and resources allow. If you have any additional information or questions about this issue, please leave a comment. For additional info about issue management, please read our Triage Process.

[Eilon]

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Issue moved from dotnet/maui#16251

• Please respond to @Eilon.

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From @Eilon on Tuesday, August 1, 2023 10:46:39 PM

Hi @Letiz0 , I wonder if this is the same as #3003 (even though in your case it's touch actions instead of keyboard/mouse).

A fix for that bug is listed here: #3003 (comment)

So it's probably worth trying that to see if it resolves your issue.

[Eilon]

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Issue moved from dotnet/maui#16251

• Please respond to @Letiz0.

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From @Letiz0 on Wednesday, August 2, 2023 1:07:43 AM

Hi @Letiz0 , I wonder if this is the same as MicrosoftEdge/WebView2Feedback#3003 (even though in your case it's touch actions instead of keyboard/mouse).

A fix for that bug is listed here: MicrosoftEdge/WebView2Feedback#3003 (comment)

So it's probably worth trying that to see if it resolves your issue.

I've tried the solution you mentioned last month, unfortunately it seemed not solving the problem.
Just like what you said it's about the touch screen instead of the mouse.

[Eilon]

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Issue moved from dotnet/maui#16251

• Please respond to @Eilon.

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From @Eilon on Wednesday, August 2, 2023 5:42:10 PM

I've tried the solution you mentioned last month, unfortunately it seemed not solving the problem. Just like what you said it's about the touch screen instead of the mouse.

Alright thanks for trying it out. I guess we'll need to investigate further. I'd say there's a strong chance we'll end up redirecting this to the WindowsAppSDK (WinUI) or WebView2 team because it's unlikely there's any Blazor- or MAUI-specific issue here.

[Eilon]

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Issue moved from dotnet/maui#16251

• Please respond to @Eilon.

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From @Eilon on Wednesday, August 2, 2023 7:48:41 PM

I've tried reproducing this on my Surface Book 3 with a touch screen and so far I am unsuccessful. I tried tapping the white part of the screen as much as possible while it loads but the app remains fully responsive to all input types. I'll keep trying.

[Eilon]

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Issue moved from dotnet/maui#16251

• Please respond to @Eilon.

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From @Eilon on Wednesday, August 2, 2023 7:52:06 PM

Alright now I can repro it! I lowered the max CPU power settings to 25% and that seemed to slow everything down enough. I then launched the app, randomly tapped on it while it loaded, and then touch doesn't work at all in the app. Interestingly, both mouse and keyboard work fine.

[Eilon]

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Issue moved from dotnet/maui#16251

• Please respond to @Letiz0.

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From @Letiz0 on Thursday, August 3, 2023 1:36:16 AM

Alright now I can repro it! I lowered the max CPU power settings to 25% and that seemed to slow everything down enough. I then launched the app, randomly tapped on it while it loaded, and then touch doesn't work at all in the app. Interestingly, both mouse and keyboard work fine.

Thanks for your efforts, and yes, the worse hardware is, the more often problem happens. It also happens when navigation and loading data from EF Core, and that's what actually annoying me. The video just shows the easiest way to reproduce it.

I found that if I force reload the page when the problem happened (e.g. NavigationManager.NavigateTo(NavigationManager.Uri, forceLoad: true)), the touch-screen would be resumed and everything worked fine, so I guess it's all about WebView2.

[Eilon]

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Issue moved from dotnet/maui#16251

• Please respond to @Eilon.

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From @Eilon on Thursday, August 3, 2023 5:26:49 PM

I was able to repro something very similar in a pure WindowsAppSDK (WinUI) + WebView2 app:

1. Create new WinUI default app in VS
2. Replace the app's content with: <WebView2 Source="https://microsoft.com/" />
3. Set your tablet PC's CPU to some extremely low speed, like this:
   
4. While launching the app w/ debugger from VS, tap the blank white app loading screen a lot
5. Eventually the app "loads", but it remains entirely a blank screen
6. Interestingly, the app did load the page because you can see it in the F12 dev tools!
   

So, I'm not quite sure if it's exactly the same bug, but it's super similar.