Swift: Click onto cell of UICollectionView and open AlertViewController - ios

Question

In my app, I am using an UICollectionView. Now I want to develop an UIAlertController, when clicking onto any cell of the collection view.
I started with following code:
extension HomeViewController: UICollectionViewDataSource {
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
…
}
// specify cells
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
….
}
// called when widget is moved
func collectionView(_ collectionView: UICollectionView, moveItemAt sourceIndexPath: IndexPath, to destinationIndexPath: IndexPath) {
…
}
// called when clicked
func collectionView(collectionView: UICollectionView, didSelectItemAtIndexPath indexPath: NSIndexPath) {
print("Got clicked!")
}
}
But somehow, "Got clicked!" is never printed.

Answer 1

try next:
extension HomeViewController: UICollectionViewDataSource, UICollectionViewDelegate {
}
or
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
...
cell.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(tap(_:))))
}
func tap(_ sender: UITapGestureRecognizer) {
let location = sender.location(in: self.collectionView)
let indexPath = self.collectionView.indexPathForItem(at: location)
if let index = indexPath {
print("Got clicked on index: \(index)!")
}
}

Answer 2

This is the version using the delegate:
extension HomeViewController: UICollectionViewDelegate {
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
print("item at \(indexPath.section)/\(indexPath.item) tapped")
}
}
Instead of using the extension you can also just add UICollectionViewDelegate and the collectionView(...didSelectItemAt:...) function to the class HomeViewController directly:
class HomeViewController: UICollectionViewDataSource, UICollectionViewDelegate {
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
print("item at \(indexPath.section)/\(indexPath.item) tapped")
}
}

Answer 3

This is because you might have placed some UIButton in the cell. Tap on some empty area in the cell then you will get the 'Got click on index'