[Not a question] WPF button visibility change after certain time of period

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C#

C#4.0

Hi,
I am new in wpf. I have code in which I want to show button for certain time of period and then change his visibilty.

Here is my code

Storyboard sb = new Storyboard();
           ObjectAnimationUsingKeyFrames objAn = new ObjectAnimationUsingKeyFrames();
           objAn.BeginTime = TimeSpan.FromSeconds(0);
           Storyboard.SetTarget(objAn, dock);
           Storyboard.SetTargetProperty(objAn, new PropertyPath(UIElement.VisibilityProperty));
           DiscreteObjectKeyFrame objd = new DiscreteObjectKeyFrame(Visibility.Visible, KeyTime.FromTimeSpan(TimeSpan.FromSeconds(0)));
           objAn.KeyFrames.Add(objd);
           DiscreteObjectKeyFrame objd1 = new DiscreteObjectKeyFrame(Visibility.Hidden, KeyTime.FromTimeSpan(TimeSpan.FromSeconds(2)));
           objAn.KeyFrames.Add(objd1);
           sb.Children.Add(objAn);
           sb.BeginAnimation(UIElement.VisibilityProperty, objAn);

dock is my button name

Waiting for reply.