Performing UI actions from message consumer

[lkomanetz]

I've got a .NET desktop app that needs to update its UI when an event has been consumed. It's not a surprise that Consume gets called from a different thread. Is there a recommended way to handle this scenario? Right now I'm registering the main window's Dispatcher into DI and injecting it into the type that implements IConsumer<T>. It works fine but the issue comes when the desktop app is starting up and there are messages in the queue to process. I was starting the bus before the main window was shown which would cause the thread dispatcher to be null and cause issues.

Is there a recommended way to handle this? Right now I'm hooked into the main window's Activated event and starting the bus at that point. It works but feels like there is a better way to do this. Here is what my consumer looks like right now.

public class JobEventsConsumer : IConsumer<JobAssigned>
{
   private readonly IMessenger _messenger; // This is coming from CommunityToolkit.Mvvm.Messaging
   private readonly Dispatcher _uiThread;

   public JobEventsConsumer(IMessenger messenger, Dispatcher uiThread) => (_messenger, _uiThread) = (messenger, uiThread);

   public Task Consume(ConsumeContext<JobAssigned> context)
   {
      // I didn't want to have a dependency on the view model from this perspective and thought that doing some sort of event
      // aggregation would be cleaner.  I'm definitely open to other ideas.
      _uiThread.Invoke(() => _messenger.Send(context.Message));
      return Task.CompletedTask;
   }
}