如何在“new RepeatBehavior（2）”完成后执行一个函数？

Question

关注代码：

XAML：

<Window x:Class="Wpf_Notice.MostrarAviso"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:Wpf_Notice"
        mc:Ignorable="d"
        Title="Notice Show" Height="300" Width="300" WindowStyle="None" ShowInTaskbar="False" ResizeMode="NoResize" Loaded="Window_Loaded">
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="*"/>
            <RowDefinition Height="auto"/>
        </Grid.RowDefinitions>
        <StackPanel Grid.Row="0">
            <!--...-->
        </StackPanel>
        <Canvas Background="Black" >
            <Canvas Canvas.Bottom="0" ClipToBounds="True" Name="canMain" Background="Red" Height="97" Width="300">
                <TextBlock FontSize="70" Name="tbmarquee" Height="74" FontFamily="Arial Black" Foreground="White" Canvas.Top="10"></TextBlock>
            </Canvas>
        </Canvas>
    </Grid>
</Window>

C＃：

private void Window_Loaded(object sender, RoutedEventArgs e)
{
    canMain.Width = ActualWidth;
    tbmarquee.Text = "Donald Trump announced on Friday a new package of measures against North Korea...";
    UpdateLayout();

    DoubleAnimation doubleAnimation = new DoubleAnimation
    {
        From = -tbmarquee.ActualWidth,
        To = canMain.ActualWidth,
        RepeatBehavior = new RepeatBehavior(2),
        Duration = TimeSpan.FromSeconds(10)
    };

    tbmarquee.BeginAnimation(Canvas.RightProperty, doubleAnimation);

    WindowState = WindowState.Maximized;
    WindowStyle = WindowStyle.None;
    Topmost = true;
}

上面的代码显示了一个从右到左的新闻，使用“DoubleAnimation”类，在传递了2个新闻RepeatBehavior = new RepeatBehavior (2)后，调用一个隐藏新闻的函数。

如何在传递2个新闻项目后调用函数？

任何解决方案？