Animate button background image

Question

I try to create animation for button background image, but don't know want i should do to get same result like at this gif. I need to do that background change from top to bottom. Thanks for any help!

Answer 1

Try do like this

CALayer *layer = [CALayer layer];
layer.frame = CGRectMake(0, self.view.bounds.size.height, self.view.bounds.size.width, self.view.bounds.size.height);
layer.backgroundColor = [UIColor blueColor].CGColor;
[self.view.layer addSublayer:layer];

CABasicAnimation *animation = [CABasicAnimation animation];
animation.keyPath = @"position.y";
animation.byValue = @(-self.view.bounds.size.height);
animation.duration = 1;

animation.fillMode = kCAFillModeForwards;
animation.removedOnCompletion = NO;
[layer addAnimation:animation forKey:@"Splash"];