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[Preview 4] Dispatcher properties are now null
See original GitHub issueDescribe the bug It appears that all dispatchers returned from UI Elements are now all null. This is a major breaking change from Preview 3 and any existing XAML apps you might want to port.
Steps to reproduce the bug
- Build a Preview 4 WinUI app.
- Inspect the
Dispatcherproperty on any control.
Expected behavior Dispatchers should not be null.
Screenshots
Version Info
NuGet package version: [Microsoft.WinUI 3.0.0-preview4.210210.4]
Windows app type:
| UWP | Win32 |
|---|---|
| Yes |
| Windows 10 version | Saw the problem? |
|---|---|
| Insider Build (xxxxx) | |
| October 2020 Update (19042) | |
| May 2020 Update (19041) | |
| November 2019 Update (18363) | |
| May 2019 Update (18362) | |
| October 2018 Update (17763) | |
| April 2018 Update (17134) | |
| Fall Creators Update (16299) | |
| Creators Update (15063) |
| Device form factor | Saw the problem? |
|---|---|
| Desktop | |
| Xbox | |
| Surface Hub | |
| IoT |
Additional context
Workaround: Use .DispatcherQueue.TryEnqueue(...).
Issue Analytics
- State:
- Created 3 years ago
- Reactions:7
- Comments:15 (8 by maintainers)
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Sorry this change wasn’t announced. We’re updating documentation to explain the effects of the change in Preview4 to not create these key UWP types in Desktop, like CoreDispatcher and ApplicationView.
Using DispatcherQueue is the right way to queue to the UI thread.
Yesterday I had to change to .DispatcherQueue.TryEnqueue(…). I confirm that this workaround works