Question

I’ve got this code from this post and everything is ok except one thing, I have this error that I dont know how to fix. this is the code:

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{

    CGPoint touchPoint = [[[event touchesForView:self] anyObject] locationInView:self];

    CGRect currentBounds = self.bounds;
    CGFloat x = touchPoint.x - CGRectGetMidX(currentBounds);

    if(x<0 && self.currentPage>=0){
        self.currentPage--;
        [self.delegate pageControlPageDidChange:self]; 
    }
    else if(x>0 && self.currentPage<self.numberOfPages-1){
        self.currentPage++;
        [self.delegate pageControlPageDidChange:self]; 
    }   
}

the error is that:

No visible @interface for 'NSObject<PageControlDelegate>' declares the selector 'pageControlPageDidChange:'.

I’ve tried to run this code with ARC, I removed the dealloc method, changed assign to weak in here:

@property (nonatomic, weak) NSObject<PageControlDelegate> *delegate;

as someone wrote in the answers, but still it isn’t working.

Please help me.

Answer 1

If in your header you just have:

@protocol PageControlDelegate;

You missed the actual definition of what the protocol is. At the bottom of that first code block in your linked post there is this code that contains the declaration of the missing protocol function:

@protocol PageControlDelegate<NSObject>
@optional
- (void)pageControlPageDidChange:(PageControl *)pageControl;
@end