如何在wpf中使文本块闪烁？

<TextBlock x:Name="myTextBlock" Text="Hello, World!" />

<TextBlock x:Name="myTextBlock" Text="Hello, World!">
    <TextBlock.Style>
        <Style TargetType="TextBlock">
            <Style.Triggers>
                <Trigger Property="Visibility" Value="Visible">
                    <Trigger.EnterActions>
                        <BeginStoryboard>
                            <Storyboard>
                                <DoubleAnimation Storyboard.TargetProperty="Opacity" From="1.0" To="0.0" Duration="0:0:1" AutoReverse="True" RepeatBehavior="Forever" />
                            </Storyboard>
                        </BeginStoryboard>
                    </Trigger.EnterActions>
                </Trigger>
            </Style.Triggers>
        </Style>
    </TextBlock.Style>
</TextBlock>

private void Button_Click(object sender, RoutedEventArgs e)
{
    myTextBlock.Visibility = Visibility.Visible;
}