Fading in and out UIButton in view

Question

In my iPad app I need to display cover-Images of publications. The user can tap on a cover to get details.

I thought about rendering UIButtons as custom buttons with the cover image as Background-image. Is it possible to fade UIButtons in and out? The user can choose a category of publications to be displayed, and ih he changes the category I wanted to fade some publications out.

Answer 1

The alpha property of any UIView (which includes a UIButton) can be animated using the block-based animations method:

[UIView animateWithDuration:0.25 animations:^{myButton.alpha = 0.0;}];

This will fade your button out over a 0.25 second period. Set the alpha to 1.0 to fade it back in again.

Answer 2

If you want the button to respond to events while it's animating, make sure to enable user interaction

[UIView
        animateWithDuration:5.0
        delay:0.0
        options:UIViewAnimationOptionAllowUserInteraction
        animations:^{ button.alpha = 0.0; }
        completion:nil];