[UITapGestureRecognizer tag]: unrecognized selector sent to instance

Question

I am having a series of imageview arranged, and assigning a TapView recognizer to it

UITapGestureRecognizer *tapRecognizer = [[UITapGestureRecognizer alloc]
                                         initWithTarget:self action:@selector(action:)];
[tapRecognizer setNumberOfTouchesRequired:1];
[tapRecognizer setDelegate:self];
imageView.userInteractionEnabled = YES;
[imageView addGestureRecognizer:tapRecognizer];

and I have defined the selector as:

-(void) action:(id)sender
  {
    NSLog(@"TESTING TAP");
    NSLog (@"%d",[sender tag]);
  }

This is getting Crashed and i am getting Error message as:-

[UITapGestureRecognizer tag]: unrecognized selector sent to instance 0x145d0210

Disfrock

Answer 1

You can use this..

UITapGestureRecognizer *tapRecognizer = [[UITapGestureRecognizer alloc]
                                         initWithTarget:self action:@selector(action:)];
[tapRecognizer setNumberOfTouchesRequired:1];
[tapRecognizer setDelegate:self];
imageView.userInteractionEnabled = YES;
imageView.tag = 1111;
[imageView addGestureRecognizer:tapRecognizer];

And in action try this..

-(void) action:(id)sender
  {
    NSLog(@"TESTING TAP");
    UITapGestureRecognizer *tapRecognizer = (UITapGestureRecognizer *)sender;
    NSLog (@"%d",[tapRecognizer.view tag]);
  }

Explaination:

UITapGestureRecognizer has not property like tag. but it has property view, from this property you can access the view with which UITapGestureRecognizer was attached.

Hope it will help you

Luetic

Welcome and feel free for any help. And please accept the answer so that other users can get help from your post – Luetic

swift equivalent please?? @NiravGadhiya – Sleave

Answer 2

Just Change your Selector Method with the following..and it will work

tapgesture will have the whole view which is tapped.. and then you can get the tag property from it as i have stated in following

-(void)action:(UITapGestureRecognizer *)tapGesture{

     NSLog(@"TESTING TAP");
        NSLog (@"%d",tapGesture.view.tag);

    }

Chamfron

Answer 3

Neither UITapGestureRecognizer nor UIGestureRecognizer declares a property or method called tag.

You can't use it. That's why you're getting the error.

On a related note. I really don't like using tag in general. There is always a better way to do what you're doing without using tag.

Viviyan

@Disfrock What are you trying to do with tag? i.e. why are you using it? If I know that I can prob suggest a better way. – Viviyan

Actually, i have a series of imageview arranged and when it scroll through the imageview i shud get the preview..as we have in iphone gallery(ios7) – Disfrock

Ah, the iPhone Photos app uses a UICollectionView to lay out the images. It works a lot like a UITableView and does all the tapping for you. That way you don't need the UITapGestureRecognizer at all and it's a lot more memory efficient to display all the photos at the same time. – Viviyan

I'd suggest looking at this tutorial... raywenderlich.com/22324/… – Viviyan

Answer 4

Swift equivalent of the accepted answer:

//use this to set up your tap gesture
let tapGesture = UITapGestureRecognizer(target: self, action: #selector(self.reactToTap(sender:)))
imageView.tag = 33
imageView.isUserInteractionEnabled = true
imageView.addGestureRecognizer(tapGesture)

This is the function which gets triggered by the tap:

@objc private func reactToTap(sender: UITapGestureRecognizer) {
            
    print("ImageView tag: ", sender.view?.tag ?? 0) //"ImageView tag: 33"
}

Concupiscence

this works! I was looking for a Swift solution for ages thanks! – Syncrisis

For anyone who is looking for a solution, do not use sender as a view. use this solution and it will work. Thanks! – Discalced

Answer 5

You cannot get tag property of UITapGestureRecognizer rather you have to get of its view's property,

You can try,

-(void)action:(id)sender
  {
     NSLog(@"TESTING TAP");
     NSLog (@"%d",[[sender view]tag]);

  }

Footy

Thanks a lot for this. The other methods did not work for me! – Lamrert