RxSchedulers.MainThreadScheduler doesn't seem to work as RxApp.MainThreadScheduler in WPF

[CyLuGh]

Hello,

I'm a bit confused as I upgraded to the latest ReactiveUI version. I saw the library changes and didn't encounter any trouble for Avalonia project, simply replacing RxApp.MainThreadScheduler to RxSchedulers.MainThreadScheduler did the trick.

But now I'm running into some thread conflicts with WPF.

I do the configuration at startup:

var app = RxAppBuilder
    .CreateReactiveUIBuilder()
    .WithWpf()
    .BuildApp();

My interaction is created as running on the main thread.

public Interaction<Unit,Unit> UpdateApplicationInteraction { get; } = new(RxSchedulers.MainThreadScheduler);

If my interaction registration is async, I will get an exception, even if I comment out any await instruction. It tells me the thread of the interaction is owning the UI element, but it should as it is created with RxSchedulers.MainThreadScheduler as parameter.

viewModel
    .UpdateApplicationInteraction.RegisterHandler( async ctx => { 
    // Update something on UI
});

If I try to store the MainThreadScheduler from the result of the RxAppBuilder, it complains about not being STA.

I don't know what I'm missing 🤔

[CyLuGh]

I'm even more confused that I created a small project to reproduce the problem and everything works fine there 🤨

[glennawatson]

Hate it when that happens. Small program definitely would be of assistance. Feels like thread creation issues or something as a instinct.

[glennawatson]

What might be useful if you can tell me the class type from the debugger for your schedulers

[CyLuGh]

Ok, I'm dumb (or we'll say overworked, it sounds better).

When I started upgrading, I tried putting the builder in my ViewModelLocator which configures my dependencies injection through the Splat.DependencyInjection.SourceGenerator (yeah, I should upgrade from that too, but DI in the builder seems to miss some methods I'm using). As it wasn't working there, I set it like the example in the startup override, but forgot to remove it from the other class. Calling the builder twice is a bad idea!

Sorry to have disturbed you.

[glennawatson]

No stress. Glad you worked it out.