在故事板中设置ViewModel布尔属性

Question

我有一个由ViewModel中的属性触发的故事板,这会触发动画启动.但是如何在动画完成后将"已保存"属性设置回False(以触发ExitAction.)

<Style TargetType="TextBlock" x:Key="FadeInOut">
        <Style.Triggers>
            <DataTrigger Binding="{Binding Saved}" Value="True">
                <DataTrigger.EnterActions>
                    <BeginStoryboard>
                        <Storyboard>
                            <DoubleAnimation Storyboard.TargetProperty="Opacity" Duration="0:0:1" From="0" To="1" />
                            <!-- set "Saved" to false when done -->
                        </Storyboard>
                    </BeginStoryboard>
                </DataTrigger.EnterActions>
                <DataTrigger.ExitActions>
                    <BeginStoryboard>
                        <Storyboard>
                            <DoubleAnimation Storyboard.TargetProperty="Opacity" Duration="0:0:1" From="1" To="0"  />
                        </Storyboard>
                    </BeginStoryboard>
                </DataTrigger.ExitActions>
            </DataTrigger>
        </Style.Triggers>
    </Style>

Answer 1

如果您可以导航到您的属性,我会建议您在结束时使用离散帧的BooleanAnimationUsingKeyFrames.

<BooleanAnimationUsingKeyFrames
            Storyboard.TargetProperty="DataContext.Saved"
            FillBehavior="HoldEnd">
            <DiscreteBooleanKeyFrame Value="False" KeyTime="0:0:1" />
</BooleanAnimationUsingKeyFrames>

既然你使用绑定Saved我假设使用DataContext应该工作.

Answer 2

您可以使用ObjectAnimationUsingKeyFrames来设置属性.我不太确定你是否可以使用其他动画,但这是我最近使用的动画.

    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Saved">
        <DiscreteObjectKeyFrame KeyTime="0">
            <DiscreteObjectKeyFrame.Value>
                <system:Boolean>False</system:Boolean>
            </DiscreteObjectKeyFrame.Value>
        </DiscreteObjectKeyFrame>
    </ObjectAnimationUsingKeyFrames>