Question

I want to let a UIImageView flash several times.

Currently I don’t know how to do that.

Actual code:

-(void)arrowsAnimate{
    [UIView animateWithDuration:1.0 animations:^{
        arrow1.alpha = 1.0;
        arrow2.alpha = 1.0;
        arrow3.alpha = 1.0;
        NSLog(@"alpha 1");
    } completion:^(BOOL finished){        

        [self arrowsAnimate2];
                    
    }];
}

-(void)arrowsAnimate2{
    [UIView animateWithDuration:1.0 animations:^{
         arrow1.alpha = 0.0;
         arrow2.alpha = 0.0;
         arrow3.alpha = 0.0;
         NSLog(@"alpha 0");
    } completion:^(BOOL finished){;}];
}

later on I call it like this:

for (int i = 0;i < 10; i++){
[self arrowsAnimate]; }

This gives me 10x alpha 1, and then 10x alpha 0. In the middle we see only one animation.
Any suggestions?

Thanks.

Answer 1

There is a simpler way to achieve a flashing animation using only 1 animation block:

aview.alpha = 1.0f;
[UIView animateWithDuration:0.5f
                      delay:0.0f 
                    options:UIViewAnimationOptionAutoreverse
                 animations:^ {
       [UIView setAnimationRepeatCount:10.0f/2.0f];
       aview.alpha = 0.0f;
} completion:^(BOOL finished) { 
       [aview removeFromSuperview]; 
}];    

The trick is to use [UIView setAnimationRepeatCount:NTIMES/2]; *_inside_* your animation block.
No need for extra functions or extra loops.