Swift 3: unrecognized selector sent to instance for gesture recognizer

Question

No matter what I do, I always get this error.

This is inside my cellForItemAtIndexPath function:

cell.postCell.profileImage.userView.addGestureRecognizer(UITapGestureRecognizer(target: self, action: "pressedUserImage:"))

and the action method:

func pressedUserImage(userView: UIImageView) {
    print(userView.superview) // error happens here.

Now of course, my userView is within a deep view hierarchy but it still has to work. For some reason it doesn't. Even if I do userImage.superview?.superview and so forth, I still get the error. I tried using #selector(pressedUserImage(_:) instead, but no luck. Tried Selector("pressedUserImage:"). Nothing.

Where am I going wrong here?

Update, here's the cellForItemAtIndexPath function:

func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
    let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "cellID", for: indexPath) as! Posts
    cell.postCell.profileImage.userView.addGestureRecognizer(UITapGestureRecognizer(target: self, action: "pressedUserImage:"))
    cell.postCell.buttonView.sharePost.addTarget(self, action: #selector(pressedShareButton), for: .touchUpInside)

    return cell
}

postCell is basically a UIView that contains the image, name, text.

Here's the error:

*** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[project.Posts pressedUserImage]: unrecognized selector sent to instance 0x7a9a65e0'

Answer 1

It looks like the problem is with your function signature. It needs to accept the gesture recognizer as a parameter, not the containing view.

Like:

func pressedUserImage(_ sender: UITapGestureRecognizer) { ... }