Delaying between animations in Objective C

Question

I'm trying to delay between turning each button's alpha to 0.0, but what I have is not working.

[UIView animateWithDuration:1.5 delay:.25 options:UIViewAnimationCurveLinear animations:^{button.alpha = 0.0;
            button2.alpha = 0.0;
            button3.alpha = 0.0;
            button4.alpha = 0.0;
            button5.alpha = 0.0;} completion:^(BOOL finished){ ; }];

How does one animate with a delay?

Answer 1

The delay is to start the animation, not a delay between each change in the animation block.

You've made things unnecessarily difficult on yourself by having a sequence of buttons and deciding to create individual variables manually instead of using an array. If you've got a collection of variables, you should usually store them in a collection of some sort.

Here's one way you could do it if they were in an array:

NSUInteger i = 0;
float duration = 1.5f;
for (UIButton *button in buttons) {
    [UIView animateWithDuration:duration delay:0.25f+duration*i UIViewAnimationCurveLinear animations:^{
        button.alpha = 0.0f;
    } completion:NULL];
    ++i;
}