Question

So, I have this code:

timer = [NSTimer scheduledTimerWithTimeInterval:4.0 target:self selector:@selector(a) userInfo:nil repeats:YES];

This code, repeat the action “a”:

-(void)a {
    self.img.image = [UIImage imageNamed:[NSString stringWithFormat:@"wp%@.jpg", i]];
    if([i isEqualToNumber:[NSNumber numberWithInt:1]]){
    i = [NSNumber numberWithInt:2];
    }else if([i isEqualToNumber:[NSNumber numberWithInt:2]]){
        i = [NSNumber numberWithInt:3];
    }else     if([i isEqualToNumber:[NSNumber numberWithInt:3]]){
        i = [NSNumber numberWithInt:1];
    }
}

This void change the image “img”, using the “i” value. I want when changing image, an effect is shown, like blurring and deblurring the “img”.

Any idea how to do this effect?

Thanks for the attention,

Alberto

Answer 1

First, it seems it would make sense to use an NSInteger or int for i. You could then write much more economically:

i += i<3 ? 1 : -2;

Don’t forget to change your format string to @"wp%i.jpg".

The animation would then be done like this:

[UIView animateWithDuration:1 
                      delay:0 
                    options: UIViewAnimationCurveEaseOut
                 animations:^{
                    self.img.image = [UIImage imageNamed:
                        [NSString stringWithFormat:@"wp%i.jpg", i]];
                             }];