bool visible = appTitleBar.Visibility is not Visibility.Visible;
if (visible)
{
NavViewVertical.Margin = new Thickness(NavViewVertical.Margin.Left,
VERTICAL_MARGIN_TOP,
NavViewVertical.Margin.Right,
NavViewVertical.Margin.Bottom);
....
}
else
{
NavViewVertical.Margin = new Thickness(NavViewVertical.Margin.Left,
VERTICAL_MARGIN_TOP_NOTVISIBLE,
NavViewVertical.Margin.Right,
NavViewVertical.Margin.Bottom);
...
}