private void OnMouseMoveRectangle(object sender, MouseEventArgs e)
{
Point ptNew = e.GetPosition(img);
BirdsEyeViewModel vm = (BirdsEyeViewModel)DataContext;
vm.RepositionBox((int)ptNew.X, (int)ptNew.Y);
}
protected override void OnMouseDoubleClick(MouseButtonEventArgs e)
{
Point ptNew = e.GetPosition(img);
BirdsEyeViewModel vm = (BirdsEyeViewModel)DataContext;
vm.RepositionBox((int)ptNew.X, (int)ptNew.Y);
vm.UpdatePosition();
}