Silverlight can'；我不明白为什么书中的动画示例不起作用

为什么这个代码不起作用

<UserControl x:Class="slv.MainPage"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
mc:Ignorable="d" d:DesignWidth="640" d:DesignHeight="480">
<Rectangle Fill="#FFFF0000" Stroke="#FF000000" Width="40" Height="40" Canvas.Top="40" x:Name="rect">
    <Rectangle.Triggers>
        <EventTrigger RoutedEvent="Rectangle.Loaded">
            <BeginStoryboard>
                <Storyboard>
                    <DoubleAnimationUsingKeyFrames Storyboard.TargetName="rect" Storyboard.TargetProperty="(Canvas.Left)" >
                        <DiscreteDoubleKeyFrame KeyTime="0:0:1" Value="300" />
                        <DiscreteDoubleKeyFrame KeyTime="0:0:9" Value="600" />
                    </DoubleAnimationUsingKeyFrames>
                </Storyboard>
            </BeginStoryboard>
        </EventTrigger>
    </Rectangle.Triggers>
</Rectangle>

---

这段代码来自关于silverlight 3的书，作者Laurence Moroney，如果这是一本书中的代码，而这正是XAML，那么它有点奇怪。我设法让这个示例运行得很好，但您缺少的是画布

<UserControl x:Class="SilverlightApplication2.MainPage"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
    mc:Ignorable="d" d:DesignWidth="640" d:DesignHeight="480">
  <Canvas x:Name="LayoutRoot">
        <Rectangle Fill="#FFFF0000" Stroke="#FF000000" Width="40" Height="40" Canvas.Top="40" x:Name="rect">
            <Rectangle.Triggers>
                <EventTrigger RoutedEvent="Rectangle.Loaded">
                    <BeginStoryboard>
                        <Storyboard>
                            <DoubleAnimationUsingKeyFrames Storyboard.TargetName="rect" Storyboard.TargetProperty="(Canvas.Left)" >
                                <DiscreteDoubleKeyFrame KeyTime="0:0:1" Value="300" />
                                <DiscreteDoubleKeyFrame KeyTime="0:0:9" Value="600" />
                            </DoubleAnimationUsingKeyFrames>
                        </Storyboard>
                    </BeginStoryboard>
                </EventTrigger>
            </Rectangle.Triggers>
        </Rectangle>
    </Canvas>
</UserControl>

下面是我通过在矩形周围添加画布修改的代码。即使它显示了任何内容，如果不使用画布将其包裹，它也不会工作，因为在动画中，它专门引用矩形相对于画布的平移

<UserControl x:Class="SilverlightApplication2.MainPage"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
    mc:Ignorable="d" d:DesignWidth="640" d:DesignHeight="480">
  <Canvas x:Name="LayoutRoot">
        <Rectangle Fill="#FFFF0000" Stroke="#FF000000" Width="40" Height="40" Canvas.Top="40" x:Name="rect">
            <Rectangle.Triggers>
                <EventTrigger RoutedEvent="Rectangle.Loaded">
                    <BeginStoryboard>
                        <Storyboard>
                            <DoubleAnimationUsingKeyFrames Storyboard.TargetName="rect" Storyboard.TargetProperty="(Canvas.Left)" >
                                <DiscreteDoubleKeyFrame KeyTime="0:0:1" Value="300" />
                                <DiscreteDoubleKeyFrame KeyTime="0:0:9" Value="600" />
                            </DoubleAnimationUsingKeyFrames>
                        </Storyboard>
                    </BeginStoryboard>
                </EventTrigger>
            </Rectangle.Triggers>
        </Rectangle>
    </Canvas>
</UserControl>

您是否收到错误，还是它没有产生您期望的结果？当我启动调试和测试页面打开并加载时，什么都没有发生。但是我等待这个例子向我展示一些矩形的动画很棒！谢谢你，约翰。本书作者写道，silverlight for browser中的标记画布取代了UserControl标记。他的一些例子在没有画布的情况下是真实的。