protected override void OnSizeChanged(int w, int h, int oldw, int oldh) { base.OnSizeChanged(w, h, oldw, oldh); var xpad = (float)(PaddingLeft + PaddingRight); var ypad = (float)(PaddingTop + PaddingBottom); var ww = w - xpad; var hh = h - ypad; _bounds = new RectF(0f, 0f, ww, hh); _bounds.OffsetTo(PaddingLeft, PaddingTop); }