C# 更改图像不能与WPF一起动态工作？

我想在按钮上动态更改图像。我想我有找到图像所需要的东西。我有som resourcedictionary用于这里的按钮：

<BitmapImage x:Key="Mark1Empty" UriSource="Marks/Tom1.png"/>
<BitmapImage x:Key="Mark1Chosen" UriSource="Marks/Ny1.png"/>

检查一下这个方法：为什么不直接看到image.Source=imagePicker；？为什么要尝试创造一个全新的形象？您确定资源URI相对于程序运行时的位置仍然有效吗？

<Button x:Name="Mark1Button"
 Height="30" Width="40" Template="{StaticResource Mark1ButtonTemplate}"
cal:Message.Attach="[Event Click] = [Action SayHello($source, $this)]"/>

   <ControlTemplate x:Key="Mark1ButtonTemplate"  TargetType="{x:Type Button}">
        <Image Name="Mark1ButtonImage"  Source="{StaticResource Mark1Empty}" />
    </ControlTemplate>

    public void SayHello(object sender, object kravsource)
    {
        var selectedButton = sender as Button;
        if (selectedButton != null)
        {
            Image image = (Image)selectedButton.Template.FindName("Mark1ButtonImage", selectedButton);
            BitmapImage imagePicker = (BitmapImage)Application.Current.FindResource("Mark1Chosen");
            image.Source = new BitmapImage(new Uri(imagePicker.UriSource.ToString(), UriKind.RelativeOrAbsolute));
            image.Stretch = Stretch.Uniform;
        }
    }