就是动画，要注意的就是EventTrigger中的SourceName就是想要实现这个功能的按钮

<StackPanel Orientation="Vertical">
    <Rectangle
        x:Name="rect"
        Width="200"
        Height="40"
        Fill="Pink" />

    <StackPanel Orientation="Horizontal">

        <StackPanel.Triggers>
            <!--普通动画-->
            <EventTrigger RoutedEvent="Button.Click" SourceName="btn_Long">
                <BeginStoryboard x:Name="myBeginStoryBoard">
                    <Storyboard>
                        <DoubleAnimation
                            Storyboard.TargetName="rect"
                            Storyboard.TargetProperty="Width"
                            From="200"
                            To="500"
                            Duration="0:0:5" />
                    </Storyboard>
                </BeginStoryboard>
            </EventTrigger>

            <!--  暂停动画，停止动画也是差不多，Resume继续也是差不多，跳过动画也是差不多  -->
            <EventTrigger RoutedEvent="Button.Click" SourceName="btn_Pause">
                <PauseStoryboard BeginStoryboardName="myBeginStoryBoard" />
            </EventTrigger>

            <!--  跳转，一下子跳到四秒  -->
            <EventTrigger RoutedEvent="Button.Click" SourceName="btn_skip">
                <SeekStoryboard
                    BeginStoryboardName="myBeginStoryBoard"
                    Origin="BeginTime"
                    Offset="0:0:4" />
            </EventTrigger>

            <!--动画速度变为5倍-->
            <EventTrigger RoutedEvent="Button.Click" SourceName="btn_speed">
                <SetStoryboardSpeedRatio BeginStoryboardName="myBeginStoryBoard" SpeedRatio="5" />
            </EventTrigger>

        </StackPanel.Triggers>

        <Button x:Name="btn_Long" Content="变长" />
        <Button x:Name="btn_Pause" Content="暂停边长" />
        <Button x:Name="btn_skip" Content="跳转动画" />
        <Button x:Name="btn_speed" Content="加速动画" />

    </StackPanel>
</StackPanel>