Get current position of UIScrollView

Question

I'm coming from Android and i'm getting a lot of headache in IOS. I need to make a scroll menu like a movie credits. I used the code below:

rol = scroll_view.contentOffset.y;
timer = [NSTimer scheduledTimerWithTimeInterval:.02 target:self selector:@selector(timer_rol) userInfo:nil repeats:YES];

-(void)timer_rol{
    [scroll_view setContentOffset:CGPointMake(0,rol) animated:YES];
rol++;
}

This code works fine, but when the user interact scrolling up or down, the view return to position before (value of rol). The question is, how can i get the current content position after scrolling

i already tried these codes, but no one works:

CGPoint point = [scroll_view contentOffset];
rol = r.y  +1;

-(void) handleGesture:(UIGestureRecognizer *) sender{}
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {}
-(void)scrollViewDidScroll:(UIScrollView *)scrollView {}

Anyone can help me?

Answer 1

In timer_rol:

[scroll_view setContentOffset:
    CGPointMake(0, scroll_view.contentOffset.y + 1) 
    animated:YES];

Or, if you don't want the X-scroll to change,

[scroll_view setContentOffset:
    CGPointMake(scroll_view.contentOffset.x, scroll_view.contentOffset.y + 1) 
    animated:YES];