SL线如何连接图片的中心点
当前情况：

想要结果：


silverlight如何用线连接到图片的中心点(或贴着图片)呢？（线的坐标已知，图片的大小及坐标已知.）代码如何实现呢？
[解决办法]
妹子的贴友情支持下，坐等大拿们解决啊
[解决办法]

<Window x:Class="WpfApplication1.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow" Height="300" Width="450" >

    <Canvas >
        <Image x:Name="image1" Stretch="None" Source="无标题.png" Canvas.Left="35" Canvas.Top="46"/>
        <Line x:Name="line1" Stroke="Green" StrokeThickness="2" X1="160" Y1="290" X2="0" Y2="0"/>
        <Button Content="Button" Canvas.Left="242" Canvas.Top="71" Width="75" Click="Button_Click"/>
    </Canvas>
</Window>

using System;
using System.Windows;
using System.Windows.Controls;

namespace WpfApplication1
{
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
        }

        private void Button_Click(object sender, RoutedEventArgs e)
        {
            Double x = Canvas.GetLeft(image1); 
 
            Double y = Canvas.GetTop(image1);

            //图片大小120*120
            x += 120 / 2;
            y += 120 / 2;

            line1.X1 = x;
            line1.Y1 = y;
        }
    }
}