Question

我想在画布内部将画布从画布右侧动画到画布左侧+标签大小，无限制。这意味着我的标签来自右侧，然后向左移动直至结束，然后再次重复。

这是我的xaml：

        <Canvas Margin="0, 0, 0, 20" Name="CanMain2" Height="30" Width="350"  >
        <Label x:Name="LabelNameSong" Content="Hello" >
            <Label.Resources>
                <Storyboard x:Key="Scroll">
                    <DoubleAnimation To="{Binding ActualWidth, ElementName=LabelNameSong}" Duration="00:00:10"
          Storyboard.TargetProperty="(Canvas.Right)"
          Storyboard.TargetName="LabelNameSong"
          RepeatBehavior="Forever"/>
                </Storyboard>
            </Label.Resources>

            <Label.Triggers>
                <EventTrigger RoutedEvent="Label.Loaded">
                    <BeginStoryboard Storyboard="{StaticResource Scroll}" />
                </EventTrigger>
                <EventTrigger RoutedEvent="Label.SizeChanged">
                    <BeginStoryboard Storyboard="{StaticResource Scroll}" />
                </EventTrigger>
            </Label.Triggers>
        </Label>
    </Canvas>

一旦我启动应用程序就崩溃了，调试器说：

无法为a上的'Right'属性设置动画 'System.Windows.Controls.Label'使用了 'System.Windows.Media.Animation.DoubleAnimation'。详情请见内在异常。

我是xaml的新手，似乎无法使其发挥作用。

Answer 1

这是因为Canvas.Right是AttachedProperty，但您尚未将该属性附加到Label

如果您将AttachedProperty添加到Label，则会让您为该值设置动画，因为该属性将注册（附加）到Label

示例：

  <Canvas Margin="0, 0, 0, 20" Name="CanMain2" Height="30" Width="350"  >
        <Label x:Name="LabelNameSong" Content="Hello" Canvas.Right="0" >
            <Label.Resources>
                <Storyboard x:Key="Scroll">
                    <DoubleAnimation To="{Binding ActualWidth, ElementName=LabelNameSong}" Duration="00:00:10"
          Storyboard.TargetProperty="(Canvas.Right)"
          Storyboard.TargetName="LabelNameSong"
          RepeatBehavior="Forever"/>
                </Storyboard>
            </Label.Resources>

            <Label.Triggers>
                <EventTrigger RoutedEvent="Label.Loaded">
                    <BeginStoryboard Storyboard="{StaticResource Scroll}" />
                </EventTrigger>
                <EventTrigger RoutedEvent="Label.SizeChanged">
                    <BeginStoryboard Storyboard="{StaticResource Scroll}" />
                </EventTrigger>
            </Label.Triggers>
        </Label>
    </Canvas>

Xaml Doubleanimation targetproperty崩溃

1 个答案: