Question

我正在WPF创建一个自定义控件，实际上是AnalogClock。这是一个非常简单的类，其模板如下所示：

public class AnalogClock {

    public static readonly DependencyProperty AnimatorProperty
        = DependencyProperty.Register("Animator", typeof(Storyboard), typeof(AnalogClock),
        new FrameworkPropertyMetadata(null));

    public Storyboard Animator {
        get { return (Storyboard)GetValue(AnimatorProperty); }
        set { SetValue(AnimatorProperty, value); }
    }

    public override void OnApplyTemplate() {
        base.OnApplyTemplate();
        if (Animator == null)
            return;

        ApplyTargetToTimeline("PART_HourHandAnimator", "PART_HourHand");

        ApplyTargetToTimeline("PART_MinuteHandAnimator", "PART_MinuteHand");

        ApplyTargetToTimeline("PART_SecondHandAnimator", "PART_SecondHand");

        ApplyTargetToTimeline("PART_IconAnimator", "PART_Icon");

        Animator.Begin(this, Template);
        // try to seek the timeline, to DateTime.Now.TimeOfDay
        // but can not ):
        Animator.Seek(this, DateTime.Now.TimeOfDay, TimeSeekOrigin.Duration);
    }

    private void ApplyTargetToTimeline(string timelineName, string targetName) {
        var timeline = Animator.Children.FirstOrDefault(t => t.Name == timelineName);
        if (timeline == null)
            throw new InvalidOperationException(string.Format(
                "The Timeline named '{0}' could not be found.", timelineName));
        Storyboard.SetTargetName(timeline, targetName);
    }
}

这是XAML：

故事板资源：

<Storyboard x:Key="Animator">

    <DoubleAnimation x:Name="PART_HourHandAnimator" From="0" To="360" Duration="12:00:00" BeginTime="00:00:00.000000"
                     RepeatBehavior="Forever" Storyboard.TargetName="{Binding}" Storyboard.Target="{Binding}"
                     Storyboard.TargetProperty="(UIElement.RenderTransform).(RotateTransform.Angle)"/>

    <DoubleAnimation x:Name="PART_MinuteHandAnimator" From="0" To="360" Duration="1:00:00" BeginTime="00:00:00.000000"
                     RepeatBehavior="Forever" Storyboard.TargetName="{Binding}" Storyboard.Target="{Binding}"
                     Storyboard.TargetProperty="(UIElement.RenderTransform).(RotateTransform.Angle)"/>

    <DoubleAnimation x:Name="PART_SecondHandAnimator" From="0" To="360" Duration="00:01:00" BeginTime="00:00:00.000000"
                     RepeatBehavior="Forever" Storyboard.TargetName="{Binding}" Storyboard.Target="{Binding}"
                     Storyboard.TargetProperty="(UIElement.RenderTransform).(RotateTransform.Angle)"/>

    <DoubleAnimation x:Name="PART_IconAnimator" From="0" To="360" Duration="00:01:00" BeginTime="00:00:00.000000"
                     RepeatBehavior="Forever" Storyboard.TargetName="{Binding}" Storyboard.Target="{Binding}"
                     Storyboard.TargetProperty="(UIElement.RenderTransform).(RotateTransform.Angle)"/>

</Storyboard>

模板：

<ControlTemplate x:Key="MyTemplate" TargetType="{x:Type ui:AnalogClock}">
    <Border>
        <Viewbox>
            <Grid>
                <Ellipse x:Name="PART_Icon" >
                    <Ellipse.RenderTransform>
                        <RotateTransform CenterX="25" CenterY="25" />
                    </Ellipse.RenderTransform>
                </Ellipse>
                <Grid>
                    <Canvas x:Name="PART_SecondHand">
                        <Ellipse RenderTransformOrigin="0.5,0.5"/>
                        <Canvas.RenderTransform>
                            <RotateTransform CenterX="60" CenterY="60"/>
                        </Canvas.RenderTransform>
                    </Canvas>
                    <Canvas>
                        <Path x:Name="PART_HourHand"  Fill="SomeBrush"
                              Data="Some data" RenderTransformOrigin="0.493,0.933">
                            <Path.RenderTransform>
                                <RotateTransform  />
                            </Path.RenderTransform>
                        </Path>
                        <Path x:Name="PART_MinuteHand"  Fill="Some brush"
                              Data="Some Data" RenderTransformOrigin="0.493,0.933">
                            <Path.RenderTransform>
                                <RotateTransform />
                            </Path.RenderTransform>
                        </Path>
                    </Canvas>
                </Grid>
            </Grid>
        </Viewbox>
    </Border>
</ControlTemplate>

风格：

<Style x:Key="MyClock" TargetType="{x:Type ui:AnalogClock}">
    <Setter Property="Animator" Value="{StaticResource Animator}"/>
    <Setter Property="Template" Value="{StaticResource MyTemplate}"/>
</Style>

正如你所看到的，这是一个非常简单的控制。好吧，它工作得很好，除了storyboard.Seek方法根本不影响。我的意思是，控件显示得很好，动画开始和我想要的一样，但是从零时间开始）;我希望我能把所有时间表的位置都带到DateTime.Now.TimeOfDay，但我不能。我尝试了TimeSeekOrigin.Duration和TimeSeekOrigin.BeginTime。但它们都不起作用。你能帮忙找到问题吗？提前致谢。

Answer 1

最后，我很幸运:)首先，当我们在Storyboard上开始Template时，不需要设置目标名称。其次，要使Storyboard.Seek生效，我们应该使用isControllable = true参数开始故事板。一起：

<Storyboard x:Key="Animator">

    <DoubleAnimation From="0" To="360" Duration="12:00:00"
                     RepeatBehavior="Forever" Storyboard.TargetName="PART_HourHand"
                     Storyboard.TargetProperty="(UIElement.RenderTransform).(RotateTransform.Angle)"/>

    <DoubleAnimation From="0" To="360" Duration="1:00:00"
                     RepeatBehavior="Forever" Storyboard.TargetName="PART_MinuteHand"
                     Storyboard.TargetProperty="(UIElement.RenderTransform).(RotateTransform.Angle)"/>

    <DoubleAnimation From="0" To="360" Duration="00:01:00"
                     RepeatBehavior="Forever" Storyboard.TargetName="PART_SecondHand"
                     Storyboard.TargetProperty="(UIElement.RenderTransform).(RotateTransform.Angle)"/>

    <DoubleAnimation From="0" To="360" Duration="00:01:00"
                     RepeatBehavior="Forever" Storyboard.TargetName="PART_Icon"
                     Storyboard.TargetProperty="(UIElement.RenderTransform).(RotateTransform.Angle)"/>

</Storyboard>

初学者代码：

public override void OnApplyTemplate() {
    base.OnApplyTemplate();
    if (Animator == null)
        return;
    // begin the storyboard on `this` control with its own `Template` and controllable
    Animator.Begin(this, Template, true);
    // the storyboard has a duration of Forever -as you can see, we did not specified any duration. Is this a default behavior?
    // while the storyboard has a duration of Forever, we have to set seekOrigin to BeginTime
    Animator.Seek(this, DateTime.Now.TimeOfDay, TimeSeekOrigin.BeginTime);
}

Storyboard.Seek不会影响

1 个答案: