ios - 无法单击自定义 UICollectionViewCell

Question

我有一个带有 imageView 和标签的自定义 UICollectionView 单元格，如下所示:

import UIKit

class PollCell: UICollectionViewCell {


@IBOutlet weak var imageView: UIImageView!

@IBOutlet weak var pollQuestion: UILabel!

}

我想让每个填充的单元格都可以点击，然后将信息从被点击的单元格传递到一个新的 ViewController。下面是填充自定义单元格的 ViewController。

import UIKit
import FirebaseDatabase
import FirebaseDatabaseUI
import FirebaseStorageUI


private let reuseIdentifier = "PollCell"

class TrendingViewController: UICollectionViewController {

var ref: FIRDatabaseReference!
var dataSource: FUICollectionViewDataSource!

override func viewDidLoad() {
    super.viewDidLoad()

    ref = FIRDatabase.database().reference()


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

    // Register cell classes

    self.dataSource = self.collectionView?.bind(to: self.ref.child("Polls")) { collectionView, indexPath, snap in
        let cell = collectionView.dequeueReusableCell(withReuseIdentifier: reuseIdentifier, for: indexPath) as! PollCell
        /* populate cell */
        cell.pollQuestion.text = snap.childSnapshot(forPath: "question").value as! String?
        let urlPollImage = snap.childSnapshot(forPath: "image_URL").value as! String?
        cell.imageView.sd_setImage(with: URL(string: urlPollImage!), placeholderImage: UIImage(named: "Fan_Polls_Logo.png"))
        //Comment
        return cell
    }

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

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

 public func collectionView(_ collectionView: UICollectionView,   didSelectItemAt indexPath: IndexPath) {
print(indexPath)
 }


 }

我还有一些代码可以“反转”填充在我的反转 ViewController 中的单元格:

import Foundation
import UIKit

class InvertedStackLayout: UICollectionViewLayout {
  let cellHeight: CGFloat = 100.00 // Your cell height here...

override func prepare() {
    super.prepare()
}

override func layoutAttributesForElements(in rect: CGRect) -> [UICollectionViewLayoutAttributes]? {
    var layoutAttrs = [UICollectionViewLayoutAttributes]()

    if let collectionView = self.collectionView {
        for section in 0 ..< collectionView.numberOfSections {
            if let numberOfSectionItems = numberOfItemsInSection(section) {
                for item in 0 ..< numberOfSectionItems {
                    let indexPath = IndexPath(item: item, section: section)
                    let layoutAttr = layoutAttributesForItem(at: indexPath)

                    if let layoutAttr = layoutAttr, layoutAttr.frame.intersects(rect) {
                        layoutAttrs.append(layoutAttr)
                    }
                }
            }
        }
    }

    return layoutAttrs
}

override func layoutAttributesForItem(at indexPath: IndexPath) -> UICollectionViewLayoutAttributes? {
    let layoutAttr = UICollectionViewLayoutAttributes(forCellWith: indexPath)
    let contentSize = self.collectionViewContentSize

    layoutAttr.frame = CGRect(
        x: 0, y: contentSize.height - CGFloat(indexPath.item + 1) * cellHeight,
        width: contentSize.width, height: cellHeight)

    return layoutAttr
}

func numberOfItemsInSection(_ section: Int) -> Int? {
    if let collectionView = self.collectionView,
        let numSectionItems = collectionView.dataSource?.collectionView(collectionView, numberOfItemsInSection: section)
    {
        return numSectionItems
    }

    return 0
}

override var collectionViewContentSize: CGSize {
    get {
        var height: CGFloat = 0.0
        var bounds = CGRect.zero

        if let collectionView = self.collectionView {
            for section in 0 ..< collectionView.numberOfSections {
                if let numItems = numberOfItemsInSection(section) {
                    height += CGFloat(numItems) * cellHeight
                }
            }

            bounds = collectionView.bounds
        }

        return CGSize(width: bounds.width, height: max(height, bounds.height))
    }
}

override func shouldInvalidateLayout(forBoundsChange newBounds: CGRect) -> Bool {
    if let oldBounds = self.collectionView?.bounds,
        oldBounds.width != newBounds.width || oldBounds.height != newBounds.height
    {
        return true
    }

    return false
    }
}

Answer 1

你必须实现UICollectionViewDelegate的这个方法

   public func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {

     debugPrint("this works")
    }

希望对你有帮助