void OnHostPopupClosed(object sender, object e)
{
_hostPopup.Child = null;
Window.Current.Activated -= OnCurrentWindowActivated;
Windows.UI.ViewManagement.InputPane.GetForCurrentView().Showing -= OnInputPaneShowing;
Windows.UI.ViewManagement.InputPane.GetForCurrentView().Hiding -= OnInputPaneHiding;
this.Content = null;
if (null != Closed)
{
Closed(this, e);
}
}