iOS - touchesMoved called only once in subclassed UIScrollView

0
votes

I am trying to drop movable UIImageViews within a subclassed UIScrollView so that I can drag them around my UIScrollView. I subclassed UISCrollView and the dropping behavior is working, but when I try to drag the images, touchesMoved is only evaluated once. The touchesMoved method in my subclass of UIScrollView looks like this:

-(void) touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event{
    if (!self.dragging) {
        [self.nextResponder touchesMoved: touches withEvent:event]; 
    }else{
        [super touchesEnded:touches withEvent:event];
    }        
}

It is being called continuously during a moving touch, as it should. Can anyone think of a reason that the touchesMoved method in my view controller would only be called once?

1
objective-ciosuiscrollviewsubclasstouchesmoved
Tried setting imageView.userInteractionEnabled = YES;? – user529758
Yes, I've set userInteractionEnabled. I should mention that upon a touchesMoved event, the imageView does move slightly in the direction that I start moving. – user1467778
Ah btw you're calling [self.nextResponder touchesMoved:withEvent:] which is explicitly prohibited by Apple's docs. Instead of sending to self.nextResponder, send to super. – user529758
And read the docs. The same thing is written in UIView's class reference. – user529758
Thanks for the response, but I'm not sure exactly what you're suggesting. I got the structure of my subclass from here: mobiledevelopertips.com/user-interface/… but I saw a lot of similar things in other StackOverflow posts. When I change it to [super touchesMoved: touches withEvent:event]; the method isn't called at all. – user1467778

1 Answers

5
votes

IOS 5: UIScrollView not pass touches to nextResponder

Instead of:

[self.nextResponder touchesMoved:touches withEvent:event]; Use:

[[self.nextResponder nextResponder] touchesMoved:touches withEvent:event];