WPF使用VisualTreeHelper进行命中测试

    <Grid MouseLeftButtonUp="Grid_MouseLeftButtonUp">
        <canvas>
            <!--三个圆形-->
            <Ellipse  Canvas.Left="30" Canvas.Top="200"  Width="130" Height="130" Fill="Blue"/>
            <Ellipse  Canvas.Left="110" Canvas.Top="0"  Width="130" Height="130" Fill="Red"/>
            <Ellipse   Canvas.Left="220" Canvas.Top="100"  Width="130" Height="130" Fill="Yellow"/>
            <TextBlock  Canvas.Left="0" Canvas.Top="0" Text="抬起鼠标左键，开始对鼠标所在点进行命中测试" />
        </Canvas>
    </Grid>

        private void Grid_MouseLeftButtonUp(object sender, MouseButtonEventArgs e)
        {
            var ellipse = GetVisual(e.GetPosition(this));
            MessageBox.Show(ellipse?.Fill?.ToString());
        }

        private Ellipse GetVisual(Point point)
        {
            HitTestResult hitResult = VisualTreeHelper.HitTest(this, point);
            var ellipse = hitResult.VisualHit as Ellipse;
            return ellipse;
        }