WPF 获取控件截图

简单记录一下：

            RenderTargetBitmap RenderBmp = new((int)VideoPlayer.ActualWidth, (int)= VideoPlayer.ActualHeight, 96, 96, PixelFormats.Pbgra32);

            RenderBmp.Render(VideoPlayer);

            Image Img = new();
            Img.Source = RenderBmp;

            _ = VideoWrap.Children.Add(Img);