public static void AnimationForm(System.Windows.Window w) { System.Windows.Media.Animation.DoubleAnimation dblAnim = new System.Windows.Media.Animation.DoubleAnimation { From = 0.0, To = 1.0, Duration = new System.Windows.Duration(TimeSpan.FromMilliseconds(500)) }; w.BeginAnimation(System.Windows.Window.OpacityProperty, dblAnim); }