Hi,

I have a storyboard as a resource in a rectangle with a simple doubleAnimation.

<Storyboard x:Name="EffectStoryboard">
    <DoubleAnimation From="0" To="500" Storyboard.TargetName="WaveEffect" Storyboard.TargetProperty="Val0" RepeatBehavior="Forever" Duration="01:00:00" />
</Storyboard>

I start the storyboard in the loaded event of the rectangle:

private void Rectangle_Loaded(object sender, RoutedEventArgs e)
{
    Rectangle rectangle = sender as Rectangle;
    if (rectangle != null)
    {
        Storyboard storyboard = rectangle.Resources["EffectStoryboard"] as Storyboard;

        //DoubleAnimation doubleAnimation = storyboard.Children[0] as DoubleAnimation;
        //if (doubleAnimation != null)
        //{
        //    doubleAnimation.BeginTime = new TimeSpan(0, random.Next(0, 60), random.Next(0, 60));
        //}

        storyboard.Begin();
    }
}

The problem is that when I uncomment the commented code, the animation won't start anymore. Even when I use non-random values in the timespan.

Why?