private void menuNew_Click(object sender, RoutedEventArgs e)
{
DrawArea.NewMeg();
btnUndo.IsEnabled = false;
btnRedo.IsEnabled = false;
btnRotateRight.IsEnabled = false;
btnRotateLeft.IsEnabled = false;
menuSave.IsEnabled = false;
menuSaveAs.IsEnabled = false;
menuDelete.IsEnabled = false;
menuDeleteAll.IsEnabled = false;
menuMoveToFront.IsEnabled = false;
menuMoveToBack.IsEnabled = false;
menuSelectAll.IsEnabled = false;
menuResetRotate.IsEnabled = false;
btnRotateRight.IsEnabled = false;
btnRotateLeft.IsEnabled = false;
txtRotate.IsEnabled = false;
}
