为什么未调用didSelectItemAtIndexPath？

Question

I have a UILabel in collection view cell and when I select it I want the background of the label to change color, but nothing happens when I click a cell? Why is that and how do I fix it? nothing is getting printed in the console.

class newview: UIViewController,UICollectionViewDataSource, UICollectionViewDelegate{
func collectionView(collectionView: UICollectionView, didSelectItemAtIndexPath indexPath: NSIndexPath) {
    print("called")
    var cell: customcell = timecollection.cellForItemAtIndexPath(indexPath) as! customcell

    cell.clabel.tag = indexPath.item
    let tapGesture = UITapGestureRecognizer(target: self, action: "choose:")
    cell.clabel.addGestureRecognizer(tapGesture)
    cell.clabel.userInteractionEnabled = true

    cell.clabel.textColor = UIColor.whiteColor()
    cell.clabel.layer.borderWidth = 0.5
    cell.clabel.layer.borderColor = UIColor.whiteColor.CGColor

     }

func choose(gest: UITapGestureRecognizer){
     let label: UILabel = gest.view as! UILabel
    label.backgroundColor = UIColor.whiteColor
     }  
}

Answer 1

I think you are tapping on label to change the color of label. didSelectitemAtIndexpath will not called if you tap the label. For that you need to add UITapGestureRecognizer to your label.

In your cellForRow try setting label.tag = indexPath.row and then add tapGesture to the label. And in the target of it change the color of label. And don't forget to set userInteractionEnable = true as label property.

EDIT

 @IBAction func btnTapped(gest: UITapGestureRecognizer) {
        print("Called")
      let label:UILabel = (gest.view as! UILabel) // Type cast it with the class for which you have added gesture
      label.backgroundColor = UIColor.redColor()
  }