UICollectionView didSelectItemAt 方法不起作用

Posted 2023-02-23

【中文标题】UICollectionView didSelectItemAt 方法不起作用

【英文标题】：UICollectionView didSelectItemAt method doesn't work

【发布时间】：2021-05-15 11:54:01

【问题描述】：

当我在 UICollectionView 中点击项目时需要给出一些逻辑，但我的 didSelectItemAt 方法不起作用

这是我的 ViewController 代码

class NewGalleryViewController: UIViewController 
var presenter: ViewToPresenterPhotoProtocol?
var builder: GalleryRequestBuilder?

@IBOutlet var collectionView: UICollectionView!
let refreshControl = UIRefreshControl()

let reuseIdentifier = "customCVCell"


@objc func refresh() 
    presenter?.refresh()


override func viewDidLoad() 
    super.viewDidLoad()
    self.collectionView.refreshControl = refreshControl
    refreshControl.addTarget(self, action: #selector(refresh), for: .valueChanged)
    self.setupPresenterIfNeed()
    presenter?.viewDidLoad()
    // Do any additional setup after loading the view.


func setupPresenterIfNeed() 
    self.collectionView.backgroundColor = UIColor.white
    if self.presenter == nil 
        let presenter = GalleryPresenter()
        presenter.view = self
        self.presenter = presenter
        self.builder = GalleryRequestBuilder()
    



extension NewGalleryViewController: UICollectionViewDelegate, UICollectionViewDataSource, UICollectionViewDelegateFlowLayout 

func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int 
    return self.presenter?.photos.count ?? 0


func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell 
    
    let cell = collectionView.dequeueReusableCell(withReuseIdentifier: reuseIdentifier, for: indexPath) as! PhotoCollectionViewCell
    
    cell.cellSetup(photo: (self.presenter?.photos[indexPath.item])!)
    
    if indexPath.row == (self.presenter?.photos.count)! - 1 
        self.presenter?.fetchNewPhotos()
    
    
    return cell


func collectionView(_ collectionView: UICollectionView,
                    layout collectionViewLayout: UICollectionViewLayout,
                    sizeForItemAt indexPath: IndexPath) -> CGSize 
    return CGSize(width: 180, height: 128)


private func collectionView(collectionView: UICollectionView, didSelectItemAtIndexPath indexPath: NSIndexPath) 
    // handle tap events
    print("test Tap")


func collectionView(_ collectionView: UICollectionView,
                    layout collectionViewLayout: UICollectionViewLayout,
                    minimumInteritemSpacingForSectionAt section: Int) -> CGFloat 
    return 1.0


func collectionView(_ collectionView: UICollectionView, layout
                        collectionViewLayout: UICollectionViewLayout,
                    minimumLineSpacingForSectionAt section: Int) -> CGFloat 
    return 20.0



extension NewGalleryViewController: PresenterToViewPhotoProtocol
func onFetchPhotoSuccess() 
    self.collectionView.reloadData()
    self.collectionView!.collectionViewLayout.invalidateLayout()
    self.collectionView!.layoutSubviews()
    self.refreshControl.endRefreshing()


func onFetchPhotoFailure(error: String) 
    print("View receives the response from Presenter with error: \(error)")
    self.collectionView.refreshControl?.endRefreshing()

这是我的 CollectioViewCell 代码

class PhotoCollectionViewCell: UICollectionViewCell 
var builder = GalleryRequestBuilder()

@IBOutlet weak var imageView: UIImageView!

override func awakeFromNib() 
    super.awakeFromNib()
    self.imageView.isUserInteractionEnabled = false
    // Initialization code


@objc func navigateToDetailView() 
    


func cellSetup(photo: Photo) 
    self.imageView.kf.setImage(with: builder.createImageUrl(name: photo.image.name))
    self.imageView.layer.cornerRadius = 8
    
    self.contentView.layer.cornerRadius = 8
    
    self.layer.borderColor = UIColor.opaqueSeparator.cgColor
    self.layer.borderWidth = 1

    
    self.layer.shadowColor = UIColor.black.cgColor
    self.layer.shadowOffset = CGSize(width: 0.0, height: 3.0)
    self.layer.shadowOpacity = 0.3
    self.layer.shadowRadius = 0.0
    self.layer.cornerRadius = 8.0
    self.layer.masksToBounds = false

我认为问题可能出在 ImageView 但删除后 didSelectItemAt 方法仍然无法正常工作。

如果您需要更多信息，这里是 GitHub 存储库https://github.com/Feetelcore/SwiftWebantGallery

【参考方案1】：

问题是您将 didSelectItemAtIndexPath 函数定义为私有。当您这样做时，它不代表 UICollectionView 的委托功能。您应该从函数中删除私有并定义如下。

    func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) 
    print("siski")    

【讨论】：

我收到警告 实例方法 'collectionView(collectionView:didSelectItemAtIndexPath:)' 几乎符合协议 'UICollectionViewDelegate' 的可选要求 'collectionView(_:didSelectItemAt:)' Make 'collectionView(collectionView:didSelectItemAtIndexPath: )' private 以使此警告静音

因为你写错了它说几乎匹配不完全匹配可能你正在做错字错误。所以只需编写 didSelect 并让 xCode 自动完成它。我下载你的回购并做同样的工作。 @伊万纽斯

【参考方案2】：

我发现您缺少delegate。在viewDidload 中添加这一行，然后重试：

collectionView.delegate = self

【讨论】：

您将private 用于didSelectItemAtIndexPath。请删除private 并再次通过建议符合委托。