private void RemoveAdorner(Canvas canvas)
{
AdornerLayer.GetAdornerLayer(canvas).Remove(Adorner);
Adorner = null;
}
private void CreateAdorner(Canvas canvas, PointEx origin, PointEx point)
{
Adorner = new SelectionAdorner(canvas);
Adorner.Zoom = GetZoomScaleTransform().ScaleX;
Adorner.SelectionOrigin = new Point(origin.X, origin.Y);
Adorner.SelectionRect = new RectEx(origin.X, origin.Y, point.X, point.Y);
Adorner.SnapsToDevicePixels = false;
RenderOptions.SetEdgeMode(Adorner, EdgeMode.Aliased);
AdornerLayer.GetAdornerLayer(canvas).Add(Adorner);
Adorner.InvalidateVisual();
}