ios - Swift - 从 UICollectionViewCell 获取 UIImage

Question

我有一个 collectionView，其中每个 cell 都包含一个 UIImage 和一个空的 UIButton 。如何显示用户点击的图片？

class ImageCollectionViewController: UIViewController, UICollectionViewDataSource, UICollectionViewDelegate, UICollectionViewDelegateFlowLayout{

    @IBOutlet weak var imageCollectionView: UICollectionView!

    let images: [UIImage] = [
        UIImage(named: "beerImage")!,
        UIImage(named: "christmasImage")!,
        UIImage(named: "goalImage")!,
        UIImage(named: "travelImage")!,
        UIImage(named: "rollerImage")!,
        UIImage(named: "giftImage")!,
        UIImage(named: "shirtImage")!,
        UIImage(named: "dressImage")!,

    ]

    let columnLayout = FlowLayout(
        itemSize: CGSize(width: 150, height: 150),
        minimumInteritemSpacing: 30,
        minimumLineSpacing: 10,
        sectionInset: UIEdgeInsets(top: 20, left: 20, bottom: 10, right: 20)
    )

    var colViewWidth: CGFloat = 0.0

    override func viewDidLoad() {

        self.imageCollectionView.collectionViewLayout = columnLayout

        super.viewDidLoad()

        imageCollectionView.dataSource = self
        imageCollectionView.delegate = self
    }

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

    func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
        let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "imageCell", for: indexPath) as! ImageCollectionViewCell

        cell.imageView.image = images[indexPath.item]
        cell.layer.cornerRadius = 2
        return cell
    }

    @IBAction func imageButtonTapped(_ sender: Any) {
        print("tapped")
    }


    @IBAction func closeButtonTapped(_ sender: Any) {
        let storyBoard: UIStoryboard = UIStoryboard(name: "Main", bundle: nil)
        let HomeViewController = storyBoard.instantiateViewController(withIdentifier: "HomeVC") as! ExampleViewController
                self.present(HomeViewController, animated: false, completion: nil)
    }
}

更新

最后我想将该图像传递给另一个 ViewController。我这样试过，但图片没有显示在另一个 ViewController 中:

ViewControllerA

var tappedImage = UIImage()
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
    tappedImage = images[indexPath.row]
}

var showPopUpView = true

override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
    print(showPopUpView)
    var vc = segue.destination as! ExampleViewController
    vc.pickedImage = self.tappedImage
    vc.ShowPopUpView = self.showPopUpView

}

ViewControllerB

    var pickedImage = UIImage()

override func viewDidLoad() {
        super.viewDidLoad()

        imagePreview.image = pickedImage

Answer 1

由于评论中的对话:

操作顺序应该是:

1. 用户点击单元格
2. 根据所选单元格的indexPath获取图片
3. 将其设置为临时变量 (tappedImage)
4. 执行转场
5. 将临时图像传递给目的地的临时图像(pickedImage)
6. 加载目的地的 View
7. 显示图像。

似乎您缺少其中一个步骤(可能是第 3 步，因为您没有在 ...didSelectItemAt indexPath... 中调用 performSegue 而它也许根本没有被调用!尝试在那里打印一些东西并检查它是否是真的)

或者您可能会打乱流程(可能您在目标的View 加载后设置图像，结果是看不到它。)

调试:

尝试在每个变量上打印您有权访问的所有变量(例如 tappedImage、pickedImage、images[indexPath.row] 等) 7 个状态并查看问题出在哪里以及您在哪里丢失了选定的图像引用

可能的问题

你没有使用 ...didSelectItemAt indexPath... 来performSegue，可能你有一个 UIButton，所以按钮正在阻止 cell 被选中。