Png图片的透明部分穿透测试

原文: Png图片的透明部分穿透测试

1       private void Window_MouseMove(object sender, MouseEventArgs e){           NavBtnList.Clear();
2                Point mouseP = e.GetPosition(this);
3                VisualTreeHelper.HitTest(this, new HitTestFilterCallback(HitFilter),
4                    new HitTestResultCallback(HitResult), new PointHitTestParameters(mouseP));
5
6                if (NavBtnList.Count > 0)
7                {
8                    for (int k = 0; k < NavBtnList.Count; k++)
9                    {
10                        IconBtn element = NavBtnList[k] as IconBtn;
11
12                        DrawingVisual drawingVisual = new DrawingVisual();
13                        using (DrawingContext context = drawingVisual.RenderOpen())
14                        {
15                            VisualBrush brush = new VisualBrush(element) { Stretch = Stretch.None };
16                            context.DrawRectangle(brush, null,
17                                new Rect(0, 0, element.ActualWidth, element.ActualHeight));
18                            context.Close();
19                        }
20
21                        //dpi可以自己设定
22                        // 获取dpi方法：PresentationSource.FromVisual(this).CompositionTarget.TransformToDevice
23                        RenderTargetBitmap bitmap = new RenderTargetBitmap((int)element.ActualWidth,
24                            (int)element.ActualHeight, 96, 96, PixelFormats.Pbgra32);
25                        bitmap.Render(drawingVisual);
26
27                        Point p = this.TranslatePoint(mouseP, element); //全局坐标转为局部坐标point
28
29                        //获取鼠标下像素颜色值
30                        var c = getImagePointColor((bitmap as BitmapSource), (int)p.X, (int)p.Y);
31                        if (c != Convert16ToColor("#00000000"))
32                        {
33                            if (element.IsEnabled)
34                            {
35                            }
36                            break;
37
38                        }
39                        bitmap.Clear();
40                    }}
41
42 1         //鼠标按下获得所有IconBtnFrame 存储在NavBtnList里
43 2         List<IconBtn> NavBtnList = new List<IconBtn>();
44 3 
45 4         public HitTestFilterBehavior HitFilter(DependencyObject dObject)
46 5         {
47 6             if (dObject is IconBtn)
48 7             {
49 8                 NavBtnList.Add(dObject as IconBtn);
50 9             }
5110             return HitTestFilterBehavior.Continue;
5211         }
5312 
5413         public HitTestResultBehavior HitResult(HitTestResult result)
5514         {
5615             return HitTestResultBehavior.Continue;
5716         }