More resources on launching dialogs? #17881

reelthymeos · 2025-01-03T14:47:00Z

reelthymeos
Jan 3, 2025

Hi,

I am following the Avalonia example for launching dialog windows: https://docs.avaloniaui.net/docs/tutorials/music-store-app/opening-a-dialog

I am still getting some Exceptions thrown when I try to follow this technique. Does anyone have some additional samples they can share where this is done? I am trying to have a separate window that launches when the user presses a button on the main window. The user will interact with this new window and data will be returned from that window to the Main View Model for processing. This is what I've done so far:

In main ViewModel, add an Interaction property, and a ICommand property:

public Interaction<AddInstrumentViewModel, NewInstrumentViewModel> ShowDialog { get; }
public ICommand AddInstrumentCommand { get; }

Then in the constructor of MainViewModel:

AddInstrumentCommand = ReactiveCommand.CreateFromTask(async () =>
{
	var addInstrumentDialogue = new AddInstrumentViewModel();
	var addInstrumentResult = await ShowDialog.Handle(addInstrumentDialogue);
});

There is a button on my MainWindowView that is bound to 'AddInstrumentCommand'.

Then in the code-behing of MainWindow I added this:

private async Task DoShowDialogAsync(IInteractionContext<AddInstrumentViewModel, NewInstrumentViewModel> interaction)
	{
		var dialog = new AddInstrumentWindow();
		dialog.DataContext = interaction.Input;

		var result = await dialog.ShowDialog<NewInstrumentViewModel>(this);
		interaction.SetOutput(result);
	}

but I don't know where this is called, if at all. And when I try to run the code, I get the exception:

ReactiveUI.UnhandledErrorException: 'An object implementing IHandleObservableErrors (often a ReactiveCommand or ObservableAsPropertyHelper) has errored, thereby breaking its observable pipeline.