silverlight 碰撞检测

原内容
http://www.andybeaulieu.com/Default.aspx?tabid=67&EntryID=95

private bool CheckCollision(FrameworkElement control1, FrameworkElement controlElem1, FrameworkElement control2, FrameworkElement controlElem2)
        {
            // first see if sprite rectangles collide
            Rect rect1 = UserControlBounds(control1);
            Rect rect2 = UserControlBounds(control2);


            rect1.Intersect(rect2);
            if (rect1 == Rect.Empty)
            {
                // no collision - GET OUT!
                return false;
            }
            else
            {
                bool bCollision = false;
                Point ptCheck = new Point();

                // now we do a more accurate pixel hit test
                for (int x = Convert.ToInt32(rect1.X); x < Convert.ToInt32(rect1.X + rect1.Width); x++)
                {
                    for (int y = Convert.ToInt32(rect1.Y); y < Convert.ToInt32(rect1.Y + rect1.Height); y++)
                    {
                        ptCheck.X = x;
                        ptCheck.Y = y;

                        List<UIElement> hits = System.Windows.Media.VisualTreeHelper.FindElementsInHostCoordinates(ptCheck, control1) as List<UIElement>;
                        if (hits.Contains(controlElem1))
                        {
                            // we have a hit on the first control elem, now see if the second elem has a similar hit
                            List<UIElement> hits2 = System.Windows.Media.VisualTreeHelper.FindElementsInHostCoordinates(ptCheck, control2) as List<UIElement>;
                            if (hits2.Contains(controlElem2))
                            {
                                bCollision = true;
                                break;
                            }
                        }
                    }
                    if (bCollision) break;
                }
                return bCollision;
            }


        }




        public Rect UserControlBounds(FrameworkElement control)
        {
            Point ptTopLeft = new Point(Convert.ToDouble(control.GetValue(Canvas.LeftProperty)), Convert.ToDouble(control.GetValue(Canvas.TopProperty)));
            Point ptBottomRight = new Point(Convert.ToDouble(control.GetValue(Canvas.LeftProperty)) + control.Width, Convert.ToDouble(control.GetValue(Canvas.TopProperty)) + control.Height);

            return new Rect(ptTopLeft, ptBottomRight);
        }

判断control1中的controlElem1是否以碰到control2的controlElem2 demo: