UICollectionViewCell - ImageViewViewImage ändern

Question

Ich habe eine UIImageView namens "Symbol" in einer UICollectionViewCell. Ich möchte das Bild in der UIImageView ändern, wenn ich auf die UICollectionViewCell tippe.

Wie mache ich das? Ich habe den folgenden Code bisher.

import UIKit 

class ViewController: UIViewController, UICollectionViewDelegateFlowLayout, UICollectionViewDataSource, UICollectionViewDelegate { 

    @IBOutlet weak var collectionView: UICollectionView! 

    let icons = [UIImage(named: "pa-w"),UIImage(named: "pi-w"),UIImage(named: "po-w"),UIImage(named: "r-w")] 
    let iconsHovered = [UIImage(named: "pa-b"),UIImage(named: "pi-b"),UIImage(named: "po-b"),UIImage(named: "r-b")] 
    let names = ["ABC", "DEF", "GHI", "JKL"] 
    let colors = ["#cccccc", "#eeeeee", "#dddddd","#aaaaaa"] 

    var screenSize: CGRect! 
    var screenWidth: CGFloat! 
    var screenHeight: CGFloat! 

    override func viewDidLoad() { 
     super.viewDidLoad() 
     // Do any additional setup after loading the view, typically from a nib. 
     collectionView.delegate = self 
     collectionView.dataSource = self 

     let layout: UICollectionViewFlowLayout = UICollectionViewFlowLayout() 
     let width = UIScreen.main.bounds.width 
     layout.sectionInset = UIEdgeInsets(top: 0, left: 0, bottom: 0, right: 0) 
     layout.itemSize = CGSize(width: width/2, height: width/2) 
     layout.minimumInteritemSpacing = 0 
     layout.minimumLineSpacing = 0 

     collectionView!.collectionViewLayout = layout 
    } 

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

    func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int { 
     return icons.count 
    } 

    func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell { 
     let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "cell", for: indexPath) as! CollectionViewCell 
     cell.icon.image = icons[indexPath.row] 
     cell.name.text = " " + names[indexPath.row] 
     cell.backgroundColor = UIColor().HexToColor(hexString: colors[indexPath.row], alpha: 1.0) 
     return cell 
    } 

    func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) { 
     let cell = collectionView.cellForItem(at: indexPath as IndexPath)! as UICollectionViewCell 

     //This line gives an error saying no ImageView called icon exists. 
     cell.icon.image = iconsHovered[indexPath.row] 
    } 

} 


extension UIColor{ 
    func HexToColor(hexString: String, alpha:CGFloat? = 1.0) -> UIColor { 
     // Convert hex string to an integer 
     let hexint = Int(self.intFromHexString(hexStr: hexString)) 
     let red = CGFloat((hexint & 0xff0000) >> 16)/255.0 
     let green = CGFloat((hexint & 0xff00) >> 8)/255.0 
     let blue = CGFloat((hexint & 0xff) >> 0)/255.0 
     let alpha = alpha! 
     // Create color object, specifying alpha as well 
     let color = UIColor(red: red, green: green, blue: blue, alpha: alpha) 
     return color 
    } 

    func intFromHexString(hexStr: String) -> UInt32 { 
     var hexInt: UInt32 = 0 
     // Create scanner 
     let scanner: Scanner = Scanner(string: hexStr) 
     // Tell scanner to skip the # character 
     scanner.charactersToBeSkipped = NSCharacterSet(charactersIn: "#") as CharacterSet 
     // Scan hex value 
     scanner.scanHexInt32(&hexInt) 
     return hexInt 
    } 
} 

Answer 1

Versuchen let cell = collectionView.cellForItem(at: indexPath as IndexPath)! as CollectionViewCell statt let cell = collectionView.cellForItem(at: indexPath as IndexPath)! as UICollectionViewCell. Dann sollten Sie Ihre Zelle als CollectionViewCell haben, die gemäß Ihrem Code eine Icon-Eigenschaft hat.