Question

In my program, I want the image in the scroll view can be detected when there is a touch. I had read the internet that there are some codes that can help to solve the problem
In a subclass .h file:

@interface AllScrollView : UIScrollView 
{
}

@end 

In the subclass .m file:

#import "AllScrollView.h"

@implementation AllScrollView

- (id)initWithFrame:(CGRect)frame 
{
  return [super initWithFrame:frame];
}

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

@end

and then I change the method - (void) touchesEnded: (NSSet *) touches withEvent: (UIEvent *) event on the main class. However, there is nothing happened and I cannot detect the touch. Do I miss something ? Could anyone give a more detail solution ? Thank you so much!

Answer 1

I used Gesture Recognizers with a scroll view, and they work fine. In your case, I would select a single tap recognizer, like this:

UITapGestureRecognizer *singleFingerTap = [[UITapGestureRecognizer alloc]
    initWithTarget:self action:@selector(handleSingleTap:)];
singleFingerDTap.numberOfTapsRequired = 1;
[self addGestureRecognizer:singleFingerTap];


- (IBAction)handleSingleTap:(UIGestureRecognizer *)sender {
    NSLog(@"Single tap detected");
}