How to fix Thread 1: Fatal error: Index out of range - ios

Question

My problem is when I click collection view it shows the data but if I click others collection view it show error:
Thread 1: Fatal error: Index out of range.
How to fix that? Thank you
Here my code
import UIKit
struct item {
var name : String
var price : String
var image : String
}
class SearchViewController: UIViewController, UICollectionViewDelegate, UICollectionViewDataSource {
var items = [item]()
#IBOutlet weak var collectionView: UICollectionView!
#IBOutlet weak var collectionviewflow: UICollectionViewFlowLayout!
override func viewDidLoad() {
super.viewDidLoad()
collectionView.delegate = self
collectionView.dataSource = self
}
func numberOfSections(in collectionView: UICollectionView) -> Int {
return 1
}
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return items.count
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "cell", for: indexPath) as! CollectionViewCell
let cellIndex = indexPath.item
cell.imageView.image = UIImage(named: items[indexPath.item].image)
cell.labelname.text = items[indexPath.item].name
cell.labelprice.text = items[indexPath.item].price
cell.contentView.layer.cornerRadius = 10
cell.contentView.layer.borderWidth = 1.0
cell.contentView.layer.borderColor = UIColor.gray.cgColor
cell.backgroundColor = UIColor.white
cell.layer.shadowColor = UIColor.gray.cgColor
cell.layer.shadowOffset = CGSize(width: 0.0, height: 2.0)
cell.layer.shadowRadius = 2.0
cell.layer.shadowOpacity = 1.0
cell.layer.masksToBounds = false
cell.layer.shadowPath = UIBezierPath(roundedRect: cell.bounds, cornerRadius: cell.contentView.layer.cornerRadius).cgPath
return cell
}
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
let vc = storyboard!.instantiateViewController(identifier: "ItemDetailViewController") as! ItemDetailViewController
vc.name = items[indexPath.item].name
vc.price = items[indexPath.item].price
vc.imagee = items[indexPath.item].image
self.navigationController?.pushViewController(vc, animated: true) }
override func viewWillDisappear(_ animated: Bool) {
items.removeAll()
}
}
extension SearchViewController : UICollectionViewDelegateFlowLayout {
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, insetForSectionAt section: Int) -> UIEdgeInsets {
return UIEdgeInsets(top: 0, left: 0, bottom: 0, right: 0)
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumInteritemSpacingForSectionAt section: Int) -> CGFloat {
return 0
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumLineSpacingForSectionAt section: Int) -> CGFloat {
return 10
}
}
and here my itemdetailsviewcontroller
import UIKit
class ItemDetailViewController: UIViewController {
var name : String = ""
var price : String = ""
var imagee : String = ""
#IBOutlet weak var labelname: UILabel!
#IBOutlet weak var image: UIImageView!
#IBOutlet weak var labelprice: UILabel!
override func viewDidLoad() {
super.viewDidLoad()
labelname.text = name
labelprice.text = price
image.image = UIImage(named: imagee)
}
}

Answer 1

Remove items.removeAll() from the viewWillDisappear(_ animated: Bool). You are changing the source data of the collectionView without it being aware. When you tap a cell a second time, the collectionView is trying to use an item from items but you emptied it when you pushed the controller on the first cell selection.