代码之家 › 专栏 › 技术社区 › Chris

Swift-从UICollectionViewCell获取UIImage

uicollectionviewcell uicollectionview swift ios

Chris · 技术社区 · 5 年前

collectionView 每个 cell UIImage 和一个空的 UIButton

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,我想把这个图像传递给另一个ViewController。我尝试了这种方式,但图片没有显示在其他ViewController中:

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

}

视图控制器B

    var pickedImage = UIImage()

override func viewDidLoad() {
        super.viewDidLoad()

        imagePreview.image = pickedImage

0 回复 | 直到 5 年前

Community CDub 5 年前

根据评论中的对话:

用户单击单元格
根据 indexPath
在临时变量中设置( tappedImage
表演环节
将临时映像传递到目标的临时映像( pickedImage
加载目标视图

似乎您错过了其中一个步骤(可能是步骤3,因为您没有打电话) performSegue 在 ...didSelectItemAt indexPath... 可能根本就没人打电话!试着在那里打印一些东西并检查它是否是真的)

之后目的地 View

调试:

点击图片 , images[indexPath.row] ,然后查看问题出在何处,以及在何处丢失选定的图像参考

可能的问题

你没有使用 表演格 ,可能你有 UIButton 所以这个按钮会阻止 cell 不会被选中。

tgrable 5 年前

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

编辑: 至于将该图像传递给下一个视图控制器,一种可能的方法是为该图像的第一个和第二个视图控制器添加属性,在 didSelectItemAt 打电话,然后用 prepare(for segue: UIStoryboardSegue, sender: Any?)

let imageToPass: UIImage?

override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
   if segue.identifier == "identifier name here" {

       // Get the new view controller using segue.destination.
       if let destVC = segue.destination as? SecondViewController {
           // Pass the selected object to the new view controller.
           destVC.image = imageToPass
       }
   }
}

Vinoth M 5 年前

func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
    let image = images[indexPath.row]
    //Result image
}

(或)

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

   //Replace your button
   cell.yourButton.tag = indexPath.row
   cell.yourButton.addTarget(self, action: #selector(self.imageButtonTapped(_:)), for: .touchUpInside)
}

按钮动作中

func imageButtonTapped(_ sender: UIButton) {
   let image = images[sender.tag]
   //Result image
}