public class MapViewOverlayControl : IMapViewOverlayControl, System.ComponentModel.INotifyPropertyChanged  

{
  //Create a Progress Bar user control
  System.Windows.Controls.ProgressBar progressBarControl = new()
  {
    //Configure the progress bar
    Minimum = 0,
    Maximum = 100,
    IsIndeterminate = true,
    Width = 300,
    Value = 10,
    Height = 25,
    Visibility = System.Windows.Visibility.Visible
  };
  //Create a MapViewOverlayControl. 
  var mapViewOverlayControl = new MapViewOverlayControl(progressBarControl, true, true, true, OverlayControlRelativePosition.BottomCenter, .5, .8);
  //Add to the active map
  MapView.Active.AddOverlayControl(mapViewOverlayControl);
  // Note: Needs QueuedTask to run
  {
    //Wait 3 seconds to remove the progress bar from the map.
    Thread.Sleep(3000);
  }
  //Remove from active map
  MapView.Active.RemoveOverlayControl(mapViewOverlayControl);
}