private void lbxItems_SelectedIndexChanged(object sender, EventArgs e)
{
if (_suppressSelectionChange)
{
return;
}
_suppressSelectionChange = true;
_layoutControl.SuspendLayout();
_layoutControl.ClearSelection();
_layoutControl.AddToSelection(new List <LayoutElement>(_lbxItems.SelectedItems.OfType <LayoutElement>()));
_layoutControl.ResumeLayout();
_suppressSelectionChange = false;
}