如何将背景颜色绑定到 ColorAnimation 的属性“To”？

Question

我有一个开关控件的彩色动画，并让背景颜色可以更改，我想将父控件的Background 属性绑定到ColorAnimation 的To 属性。我尝试了很多，但没有人工作。我该怎么做？

开关控制方式：

<Setter Property="Template">
<Setter.Value>
    <ControlTemplate TargetType="CheckBox">
        <Viewbox Stretch="Uniform">
            <Border x:Name="layer" Width="35" Height="20" CornerRadius="10,10,10,10" 
                            Background="{TemplateBinding Background}" BorderBrush="{TemplateBinding BorderBrush}"
                            BorderThickness="{TemplateBinding BorderThickness}">
                <Canvas Canvas.Top="0" Canvas.Left="0">
                    <Ellipse x:Name="circle" Fill="Gray" Stroke="DarkGray" StrokeThickness="0" 
                                 Width="20" Height="20">
                        <Ellipse.RenderTransform>
                            <TranslateTransform X="0" Y="0"/>
                        </Ellipse.RenderTransform>
                    </Ellipse>
                </Canvas>
            </Border>
        </Viewbox>
        <ControlTemplate.Triggers>
            <Trigger Property="IsChecked" Value="True">
                <Trigger.EnterActions>
                    <BeginStoryboard>
                        <Storyboard>
                            <ColorAnimation Storyboard.TargetName="layer" 
                                                    Storyboard.TargetProperty="Background.Color"
                                                    To="LightGreen"
                                                    Duration="0:0:0.3"/>
                            <DoubleAnimation Storyboard.TargetName="circle"
                                                     Storyboard.TargetProperty="(Ellipse.RenderTransform).(TranslateTransform.X)"
                                                     To="15"
                                                     Duration="0:0:0.3"/>
                        </Storyboard>
                    </BeginStoryboard>
                </Trigger.EnterActions>
                <Trigger.ExitActions>
                    <BeginStoryboard>
                        <Storyboard>
                            <ColorAnimation Storyboard.TargetName="layer" 
                                                    Storyboard.TargetProperty="Background.Color"
                                                    Duration="0:0:0.3"
                                                        To="{TemplateBinding Background}"/>
                            <DoubleAnimation Storyboard.TargetName="circle"
                                                     Storyboard.TargetProperty="(Ellipse.RenderTransform).(TranslateTransform.X)"
                                                     To="0"
                                                     Duration="0:0:0.3"/>
                        </Storyboard>
                    </BeginStoryboard>
                </Trigger.ExitActions>
            </Trigger>
        </ControlTemplate.Triggers>
    </ControlTemplate>
</Setter.Value>
</Style>

ColorAnimation部分：

    <ColorAnimation Storyboard.TargetName="layer" 
                    Storyboard.TargetProperty="Background.Color"
                    To="{TemplateBinding Background}"
                    Duration="0:0:0.3"/>

Answer 1

你不能在彩色动画中使用绑定，否则你会得到这个错误 “无法冻结此 Storyboard 时间线树以供跨线程使用”，更多信息请点击此处： WPF Animation "Cannot freeze this Storyboard timeline tree for use across threads".

现在，如果您想解决问题，您可以做一个静态资源，它代表您的父控件的背景颜色，如下所示：

 <Color  A="255"
            R="100"
            G="0"
            B="0"
            x:Key="resource" />

然后您可以将此资源分配给您的颜色动画属性，如下所示：

<ColorAnimation Storyboard.TargetName="layer"
                                                        Storyboard.TargetProperty="Background.Color"
                                                        Duration="0:0:0.3"
                                                        To="{StaticResource ResourceKey=resource }" />

希望对你有帮助。