public sealed class PresentationView 

//Assume we want to open a view for a particular presentation or activate a view if one is already open

//A presentation project item is an item that appears in the Presentation folder in the Catalog pane.
PresentationProjectItem presentationItem = Project.Current.GetItems<PresentationProjectItem>()
                                             .FirstOrDefault(item => item.Name.Equals(presentationName));

//Reference a presentation associated with a presentation project item
if (presentationItem != null)
{
  //Get the presentation associated with the presentationItem
  Presentation presentationToOpen = await QueuedTask.Run(() => presentationItem.GetPresentation());

  //Next check to see if a presentation view is already open that references the presentation
  foreach (var pane in ProApp.Panes)
  {
    var prePane = pane as IPresentationPane;
    if (prePane == null)  // Not a presentation view, continue to the next pane
      continue;

    //if there is a match, activate the view
    if (prePane.PresentationView.Presentation == presentationToOpen)
    {
      (prePane as Pane).Activate();
      return;
    }
  }

  //No pane found, activate a new one - must be called on UI
  IPresentationPane iNewPresentationPane = await ProApp.Panes.CreatePresentationPaneAsync(presentationToOpen); //GUI thread
}

//Note: Call within QueuedTask.Run()
Presentation presentation = PresentationView.Active.Presentation;
//Must be on QueuedTask
await QueuedTask.Run(() =>
{
  // add a blank page with with title and paragraph body text element
  presentation.AddBlankPage(BlankPageTemplateType.TitleAndParagraph, -1);
});

//For UI context changes associated with a presentation, subscribe to the PresentationView
//event - views activated/deactivated, views opened/closed
ArcGIS.Desktop.Presentations.Events.PresentationViewEvent.Subscribe((args) =>
{
  //get the affected view and presentation
  var view = args.PresentationView;
  var presentation = args.PresentationView?.Presentation;
  if (presentation == null)
  {
    //FYI presentationview and/or presentation can be null...
    //eg closed, deactivation
  }
  //Check what triggered the event and take appropriate action
  switch (args.Hint)
  {
    case PresentationViewEventHint.Activated:
      // Presentation view activated
      break;
    case PresentationViewEventHint.Opened:
      //A PresentationView has been initialized and opened
      break;
    case PresentationViewEventHint.Deactivated:
      // Presentation view deactivated
      break;
    case PresentationViewEventHint.Closing:
      //Set args.Cancel = true to prevent closing
      break;
    case PresentationViewEventHint.ExtentChanged:
      //presentation view extent has changed
      break;
    case PresentationViewEventHint.DrawingComplete:
      break;
    case PresentationViewEventHint.PauseDrawingChanged:
      break;
  }
});