Some WinUI rendering (e.g. showing `ContextFlyout`) very slow on client’s computer

Question

When running my framework dependent, unpackaged, .NET 8, WinUI 3 app (with all the latest dependencies) on my client’s computer (Windows 11) some UI functionality is very slow.

Examples:

• When right-clicking on an item in order to open ContextFlyout menu it takes sometimes 2 seconds before it shows. Continuing right-clicking might reveal the menu quicker. Then it’s slower again.

• Another example is the CalendarDatePicker: also like 2 seconds before the calendar view is displayed.

• Opening ContentDialog is also slow, 2 - 3 seconds.

On my computer it quite snappy and runs fine once it loads.

The older WinForms version of the app (which uses the same lower layer dependencies, just the UI layer is WinForms instead of WinUI 3) does not have this problem on my client’s computer.

It’s hard to image what software would interact with mouse clicks. But other apps do not have this problem so I don’t think there’s another app interfering. I have allowed the app in Windows Defender.

Any tips I could try out would be highly appreciated.

Answer 1

Whatever this was, compiling against WinAppSdk 1.6.0, solved the problem. Everything is really snappy now on the same computer! :)

Update

Actually, it was Google Drive. It had nothing to do with WinAppSdk. The app (which was published framework dependent to a folder) was running in a Google Drive synced folder (offline mode). Simply copying the folder outside Google Drive and running it from there it's not slow anymore.

On other computers, the app runs fine from within Google Drive folder, so it's just on this particular computer.