public Layout Layout {get;}

//Set the layout's element selection.

await QueuedTask.Run(() =>
{
  Element rec = layoutView.Layout.FindElement("Rectangle");
  Element rec2 = layoutView.Layout.FindElement("Rectangle 2");

  List<Element> elmList = new List<Element>();
  elmList.Add(rec);
  elmList.Add(rec2);

  layoutView.SelectElements(elmList);
});

//This sample checks to see if a layout project item already has an open application pane.  
//If it does, it checks if it is the active layout view, if not, it creates, activates and opens a new pane.

//Reference a layoutitem in a project by name
LayoutProjectItem layoutItem = Project.Current.GetItems<LayoutProjectItem>().FirstOrDefault(item => item.Name.Equals("Layout View"));

//Get the layout associated with the layoutitem
Layout lyt = await QueuedTask.Run(() => layoutItem.GetLayout());
      
//Iterate through each pane in the application and check to see if the layout is already open and if so, activate it
foreach (var pane in ProApp.Panes)
{
  var layoutPane = pane as ILayoutPane;
  if (layoutPane == null)  //if not a layout pane, continue to the next pane
    continue;
  if (layoutPane.LayoutView.Layout == lyt)  //if the layout pane does match the layout, activate it.
  {
    (layoutPane as Pane).Activate();
    layoutPane.Caption = "This is a test";
    System.Windows.MessageBox.Show(layoutPane.Caption);
    return;
  }
}
//Otherwise, create, open, and activate the layout if not already open
ILayoutPane newPane = await ProApp.Panes.CreateLayoutPaneAsync(lyt);

//Zoom to the full extent of the layout
await QueuedTask.Run(() => newPane.LayoutView.ZoomTo100Percent());

//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;