Cannot Click Custom UICollectionViewCell - ios

Question

I have a custom UICollectionView cell with an imageView and a label, as listed below:
import UIKit
class PollCell: UICollectionViewCell {
#IBOutlet weak var imageView: UIImageView!
#IBOutlet weak var pollQuestion: UILabel!
}
I want to make each populated cell clickable and then pass information from that clicked cell into a new ViewController. Below is the ViewController that populates the custom cell.
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)
}
}
I also have some code to "invert" the cells that populate in my inverted ViewController:
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

You must to implement this method of UICollectionViewDelegate
public func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
debugPrint("this works")
}
I hope this helps you

Answer 2

This Function used to select the row of your collection view
public func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
}
Then you use function call. Whatever you need, just Defined the inside function. And easily called the function during the selected the row (inside the didSelectItemAt indexPath)

Answer 3

Make sure you have enabled UserIntraction for both UILabel and UIImageView, because both have default value as false.
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.userInteractionEnabled = true;
cell.imageView.userInteractionEnabled = true;
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
}
Then you need to use of UICollectionViewDelegate method:
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
// handle tap events
}

Answer 4

Add a segue in your storyboard from the cell to the view controller you want to transition to. You can use the prepare for segue method, prepare(for:sender:), to pass your data. Using the segue (UIStoryboarySegue documentation) parameter, you can access the 'destinationViewController`.
Check out the View Controller for iOS Programming Guide: Using Segues for more information about using segues.