public static LayoutView Active {get;}

//This example references the active layout view.  Next it finds a couple of elements and adds them to a collection. 
//The elements in the collection are selected within the layout view.  Finally, the layout view is zoomed to the
//extent of the selection.

// Make sure the active pane is a layout view and then reference it
if (LayoutView.Active != null)
{
  LayoutView lytView = LayoutView.Active;
  //Reference the layout associated with the layout view
  Layout lyt = await QueuedTask.Run(() => lytView.Layout);

  //Find a couple of layout elements and add them to a collection
  Element map1 = lyt.FindElement("Map1 Map Frame");
  Element map2 = lyt.FindElement("Map2 Map Frame");
  List<Element> elmList = new List<Element>();
  elmList.Add(map1);
  elmList.Add(map2);

  //Set the selection on the layout view and zoom to the selected elements
  await QueuedTask.Run(() => lytView.SelectElements(elmList));
  await QueuedTask.Run(() => lytView.ZoomToSelectedElements());
}

// Make sure the active pane is a layout view and then reference it
if (LayoutView.Active != null)
{
  LayoutView lytView = LayoutView.Active;
  //Reference the layout associated with the layout view
  Layout lyt = await QueuedTask.Run(() => lytView.Layout);

  //Find a couple of layout elements and add them to a collection
  Element map1 = lyt.FindElement("Map1 Map Frame");
  Element map2 = lyt.FindElement("Map2 Map Frame");
  List<Element> elmList = new List<Element>();
  elmList.Add(map1);
  elmList.Add(map2);

  //Set the selection on the layout view and zoom to the selected elements
  await QueuedTask.Run(() => lytView.SelectElements(elmList));
  await QueuedTask.Run(() => lytView.ZoomToSelectedElements());
  return true;
}
return false;

//Return the page number that corresponds to the page name field for an index feature

Layout layout = LayoutView.Active.Layout;

//Perform on the worker thread
await QueuedTask.Run(() =>
{
  SpatialMapSeries SMS = layout.MapSeries as SpatialMapSeries;
  Row msRow = SMS.CurrentRow;
  System.Windows.MessageBox.Show(SMS.FindPageNumber(msRow.GetOriginalValue(msRow.FindField("NAME")).ToString()));
});

//Reference the active layout view.

//Confirm if the current, active view is a layout view.
//If it is, do something.
LayoutView activeLayoutView = LayoutView.Active;
if (activeLayoutView != null)
{
  // do something
}

LayoutView layoutView = LayoutView.Active;
//Unselect one element.
var elementToUnSelectInView = layout.FindElements(new List<string>() { "MyPoint" }).FirstOrDefault();
layoutView.UnSelectElement(elementToUnSelect);
//Unselect multiple elements.
var elementsToUnSelectInView = layout.FindElements(new List<string>() { "Point 1", "Line 3", "Text 1" });
layoutView.UnSelectElements(elementsToUnSelect);