单击集合视图中的单元格即可过渡到视图控制器

Question

I need to perform a transition to a view controller on the click of a cell (contains only label) in a collection view. I have tried using:

collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath)

as well as:

override func prepare(for segue: UIStoryboardSegue, sender: Any?)

but none of them work meaning they are not getting invoked. The cell has been set to User Interaction enabled and also Multiple touch enabled. Please let me know how to fix this.

I am using Swift 4.1 and Xcode 9.4.1.

Code:

   class MyCasesViewController: UIViewController, UICollectionViewDelegate, UICollectionViewDataSource{

    var MyCases : [[String]] = [[]]
    var textPassedOver : String?



    @IBOutlet weak var label: UILabel!

    override func viewDidLoad() {
        super.viewDidLoad()

        label.text = textPassedOver



        // Uncomment the following line to preserve selection between presentations
        // self.clearsSelectionOnViewWillAppear = false

        // Register cell classes
        //self.collectionView!.register(UICollectionViewCell.self, forCellWithReuseIdentifier: reuseIdentifier)

        // Do any additional setup after loading the view.
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }



    // MARK: UICollectionViewDataSource

     func numberOfSections(in collectionView: UICollectionView) -> Int {
        // #warning Incomplete implementation, return the number of sections
        return MyCases.count
    }


     func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        // #warning Incomplete implementation, return the number of items
        return MyCases[0].count
    }

     func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
        collectionView.delegate = self
        let cell = collectionView.dequeueReusableCell(withReuseIdentifier: reuseIdentifier, for: indexPath) as! CustomViewCell

        // Configure the cell

        cell.label.text = MyCases[indexPath.section][indexPath.item]

        if(indexPath.section == 0){
           cell.label.font = UIFont(name: "bold", size: 6)
        }else{
            cell.label.font = UIFont(name: "HelveticaNeue", size: 14)
        }
        //cell.isSelected = true

        return cell
    }

    func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
        performSegue(withIdentifier: "CaseDetails", sender: self )
    }

    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
        print(segue.identifier)
        if(segue.identifier == "CaseDetails"){
            let destinationVC = segue.destination as! CaseDetailViewController
          //CaseDetailViewController.delegate = self
            destinationVC.textPassedOver = "pass this text"
        }
    }

//    func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
//        collectionView.allowsSelection = true
//       print("is it here")
//        if(indexPath.section == 1 ){
//            print("Hurray")
//            let viewController = UIViewController()
//            self.navigationController?.pushViewController(viewController, animated: true)
//        }
//    }

//    func collectionView(_ collectionView: UICollectionView, didSelectItemAtIndexpath indexpath: IndexPath){
//        print("is it here now")
//        print(indexpath.section)
//        print(indexpath.item)
//    }
//
//    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
//        if(segue.identifier == "CaseDetails" ){
//            let cell = sender as! CustomViewCell
//            var destination = segue.destination as! CaseDetailViewController
//            destination.flag = "Hurray"
//        }
//    }






    // Uncomment this method to specify if the specified item should be selected
     func collectionView(_ collectionView: UICollectionView, shouldSelectItemAt indexPath: IndexPath) -> Bool {
        return true
    }



}

Answer 1

您需要在viewDidLoad设置委托

self.collectionView.delegate = self

Answer 2

Okay I got it worked.. there is nothing wrong in my code . For a strange reason I found that if I apply constraints to my collectionview the onclick event does not trigger the didselectitemat function. When I have removed those constraints it worked.