WPF之获取当前某个ellipse控件

[qiancaoyxp]

当前屏幕上有多个ellipse画成的圆，如何获取某一个圆，让它的颜色改变？小菜刚接触WPF，请教高手。。谢谢。

[Bonjour-你好]

<Window x:Class="WpfTest.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow" Height="350" Width="525" MouseUp="Window_MouseUp" >
    <Canvas>
        <Ellipse Width="30" Height="30" Fill="Red" Canvas.Left="46" Canvas.Top="41"/>
        <Ellipse Width="30" Height="30" Fill="Green" Canvas.Left="74" Canvas.Top="137"/>
        <Ellipse Width="30" Height="30" Fill="Blue" Canvas.Left="135" Canvas.Top="67"/>
    </Canvas>
</Window>

using System.Windows;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Shapes;

namespace WpfTest
{
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
        }

        private void Window_MouseUp(object sender, MouseButtonEventArgs e)
        {
            Ellipse ellipse = e.OriginalSource as Ellipse;
            if (ellipse != null) {
                ellipse.Fill = new SolidColorBrush { Color = Colors.Gray };
            }
        }
    }
}