WPF Update UI Before Performing Other Operations

Question

I'm using WPF, Caliburn.Micro and WPF Extended Toolkit to display a busy indicator when I change the view that is displaying. The issue is that the busy indicator never displays between the views being switched (which is why I need it).

How It Works While Broken

1. Click menu item
2. Set IsBusy = true
3. No busy indicator shows up
4. Change view (ChangeActiveItem(ViewModel, bool))
5. View displays
6. Busy indicator displays

How It Should Work

1. Click menu item
2. Set IsBusy = true
3. Busy Indicator displays
4. Change view
5. View Displays and renders fully
6. IsBusy = false
7. BusyIndicator hides

ShellView (BusyIndicator Snippet)

<xctk:BusyIndicator IsBusy="{Binding IsBusy}">
    <ContentControl x:Name="ActiveItem" />
</xctk:BusyIndicator>

NavigationViewModel (Method - Fires when clicking a menu item)

public void NavigationItemClicked(NavigationItem item)
{
    _eventAggregator.PublishOnUIThread(new NavigationItemClicked(item.ViewModelType));
}

ShellViewModel (Method - Catches message from NavigationViewModel.NavigationItemClicked)

public void Handle(NavigationItemClicked message)
{
    worker = new BackgroundWorker();

    worker.DoWork += (s, e) =>
    {
        ChangeActiveItem(QuestDetails, true);
        IsBusy = false;
    };

    IsBusy = true;
    worker.RunWorkerAsync();
}

Also Tried

1. Changing 'PublishOnUiThread' to 'PublishOnBackgroundThread'
2. Ayyappan Subramanian suggestion

Answer 1

• change isBusy status in runworkercompleted
• make isbusy public property
• in page constructor add datacontext

• IsBusy="{Binding IsBusy,UpdateSourceTrigger=PropertyChanged }"

  public void Handle(NavigationItemClicked message)
   {
   worker = new BackgroundWorker();
  
   worker.DoWork += (s, e) =>
    {
      ChangeActiveItem(QuestDetails, true);
  IsBusy = false;
  };
   worker.RunWorkerCompleted += (s, e) =>
   {
  
    IsBusy = true;
   };
  
   worker.RunWorkerAsync();
  }