Calling PropertyChanged events from worker threads

[ArchibaldMacdonald-cyacomb]

I'm having trouble finding official information on calling PropertyChanged events from off the main UI-thread. I've tracked down 2 github issues that suggest one shouldn't, but I'm not sure how in-date these are with the current state of Avalonia framework:

#7644
#5550

So a couple of questions:

1. Definitively, is it still the case that can you not call PropertyChanged off-thread?
2. Why does it currently work in cases I've witnessed, and is this undefined behaviour?
3. Can we have official documentation on this for the future?
4. Can we have warnings/exceptions in the future such that it doesn't silently "just work" or is this by design?

[timunie]

3 --> https://docs.avaloniaui.net/docs/guides/development-guides/accessing-the-ui-thread

[ArchibaldMacdonald-cyacomb]

Hi Timunie,

The docs you linked talk about how to access the UI thread, but don't give much info of when and why.

[timunie]

everything that updates the UI, so all events the UI needs to handle. Feel free to add a PR to the docs to clarify it further.

[ArchibaldMacdonald-cyacomb]

Appreciate it Timunie, I needed it written down explicitly. (And answers questions 1 and 3.)

[robloo]

Long-term there might be things that Avalonia should do to be more similar to WPF here: https://stackoverflow.com/questions/1321423/does-wpf-databinding-marshall-changes-to-the-ui-thread