private void rect_window_fadein() { DoubleAnimation fadingAnimation = new DoubleAnimation(); fadingAnimation.From = 0; fadingAnimation.To = 1; fadingAnimation.Duration = new Duration(TimeSpan.FromSeconds(2)); LoginRectangle.BeginAnimation(Rectangle.OpacityProperty, fadingAnimation); LoginButton.BeginAnimation(Button.OpacityProperty, fadingAnimation); ExitRectangle.BeginAnimation(Button.OpacityProperty, fadingAnimation); UsernameTextbox.BeginAnimation(TextBox.OpacityProperty, fadingAnimation); PasswordTextbox.BeginAnimation(TextBox.OpacityProperty, fadingAnimation); }