Webview2 VSTO Office Plugin: Meeting / Email window gets into freezing state while opening form (custom task pane)

[ManojPatelA]

Hello,

With Outlook plugin custom task pane and WebView2 control it seems a known issue where the form gets misplaced when you load the form on different monitor scaling #820

Along with this behaviour, I see one more issue where meeting / email window gets into freezing state as soon as form gets open. This behaviour is consistent and happens with just one monitor as well.

Steps to reproduce:
1. Keep your monitor scaling to 100% (recommended option)
2. Open outlook
3. Change monitor scaling to 125%
4. Open new meeting / email window and click on your plugin ribbon button
Consistently this makes meeting window frozen, this can easily happen when you work from home and office and have different resolution / scaling.

As per article Handle high DPI and DPI scaling in office solution workaround is to use Office DPI compatibility model however, this freezing issue still happens. With compatibility mode setting misplacing of the form issue gets resolved.

WebView2 runtime: 114.0.1823.79
SDK: 1.0.1823.32

Is there any fix / workaround for this issue ? If not what's the timeline for fixing out this issue? Is fix will be only available with OS win11 as per the above github article ?

Thanks,

AB#45893635

[novac42]

@ManojPatelA Thanks for reporting the issue. If possible may you share a sample app for us to repro?

[champnic]

@ManojPatelA You are right that this sounds like another DPI related issue. When are you creating the WebView2 control? When the addin is loaded, or only when the plugin button is clicked? If you were trying to display an existing WebView2 after the DPI change then that could be the source of the mismatch and failure. If so, could you try only creating the WebView2 when the button is clicked so that the WebView2 matches the DPI and awareness of the parent window?

[ManojPatelA]

@champnic I have tried both the ways creating wevvie2 control, while opening of window as well as clicking on the button getting exactly same result. Even I have added one winform button (on top of task panel along with WebView2 control) and on click of that button opening of Winform pop up with completely new webview2 control there as well it's the same issue.

[ManojPatelA]

@ManojPatelA Thanks for reporting the issue. If possible may you share a sample app for us to repro?

I have tried with my actual project as well as with small new add in both have exactly same result. Due to some setup issue I am unable to share but will do it soon. Thanks

[ManojPatelA]

@ManojPatelA Thanks for reporting the issue. If possible may you share a sample app for us to repro?
Here is the sample outlook plugin
SampleOutlookPlugin_Webview2_.zip

[champnic]

Thanks for sharing the sample, I'll try to reproduce the issue now. Are you seeing this on all versions of Windows, or only a specific one/range?

[champnic]

@ManojPatelA We believe this is a DPI mismatch issue when Outlook.exe, which is System aware, is somehow still responding and changing their DPI in a way that we can't detect and match in the WebView2 browser process HWND. We have work planned with #985 which would alleviate this issue altogether by removing cross-process HWND parenting. If you wanted to try out that work (it's not complete yet) you can set:
Environment.SetEnvironmentVariable("COREWEBVIEW2_FORCED_HOSTING_MODE", "COREWEBVIEW2_HOSTING_MODE_WINDOW_TO_VISUAL");

[ManojPatelA]

@ManojPatelA We believe this is a DPI mismatch issue when Outlook.exe, which is System aware, is somehow still responding and changing their DPI in a way that we can't detect and match in the WebView2 browser process HWND. We have work planned with #985 which would alleviate this issue altogether by removing cross-process HWND parenting. If you wanted to try out that work (it's not complete yet) you can set: Environment.SetEnvironmentVariable("COREWEBVIEW2_FORCED_HOSTING_MODE", "COREWEBVIEW2_HOSTING_MODE_WINDOW_TO_VISUAL");