public void Activate()

var mapPanes = ProApp.Panes.OfType<IMapPane>();
foreach (Pane pane in mapPanes)
{
  if (pane.Caption == "MyMap")
  {
    pane.Activate();
    break;
  }
}

//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());

//Activate an already open layout view.
//A layout view may be open but it may not be active.

//Find the pane that references the layout and activate it. 
//Note - there can be multiple panes referencing the same layout.
foreach (var pane in ProApp.Panes)
{
  var layoutPane = pane as ILayoutPane;
  if (layoutPane == null)  //if not a layout view, continue to the next pane
    continue;
  if (layoutPane.LayoutView.Layout == layout) //activate the view
  {
    (layoutPane as Pane).Activate();
    return;
  }
}

Report report = Project.Current.GetItems<ReportProjectItem>().FirstOrDefault().GetReport();
var reportPane = FrameworkApplication.Panes.FindReportPanes(report).Last();
if (reportPane == null)
  return;
//Activate the pane
(reportPane as ArcGIS.Desktop.Framework.Contracts.Pane).Activate();
//Get the "ReportView" associated with the Report Pane.
ReportView reportView = reportPane.ReportView;