快速错误-使用未声明的类型“cells”-集合视图

Question

对于Swift编程来说，这是一个全新的过程，我的错误是什么原因？我该如何修复它呢？非常感谢。

import UIKit
import Photos


class PhotosViewController: UIViewController, UICollectionViewDelegate, UICollectionViewDataSource , UICollectionViewDelegateFlowLayout, UIImagePickerControllerDelegate, UINavigationControllerDelegate

{

    @IBOutlet weak var myCollectionView: UICollectionView!


    var imagesArray = [UIImage]()

    override func viewDidLoad(){
        super.viewDidLoad()
        myCollectionView.delegate = self
        myCollectionView.dataSource = self

    }

    @IBAction func addPhoto(_ sender: AnyObject) {

        let picker:UIImagePickerController = UIImagePickerController()
        picker.sourceType = .photoLibrary
        picker.mediaTypes = UIImagePickerController.availableMediaTypes(for: .photoLibrary)!

        picker.delegate = self
        picker.allowsEditing = false
        self.present(picker, animated: true, completion: nil)
    }

    func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
        let cell = collectionView.dequeueReusableCellWithReuseIdentifier("cell", forIndexPath: indexPath) as! cell


        cell.configurecell(imagesArray[indexPath.row])

        return cell

    }


    func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {

        return imagesArray.count

    }



    func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : Any]) {
        if let pickedimage = (info[UIImagePickerControllerOriginalImage] as? UIImage){
            imagesArray = [pickedimage,pickedimage,pickedimage]//Will store three selected images in your array
            myCollectionView.reloadData()
        }
        dismiss(animated: true, completion: nil)
    }
}

Answer 1

以下是将集合视图单元格强制转换为自定义类类型的更好方法，而不需要“强制转换”（当您使用

func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
    let _cell = collectionView.dequeueReusableCellWithReuseIdentifier("cell", for: indexPath)
    guard let cell = _cell as? CollectionViewCell else { return _cell } // Replace "CollectionViewCell" with your custom class name
    cell.configurecell(imagesArray[indexPath.row])
    return cell
}

如您所见，我使用 而不是 将单元格强制转换为类型 。

Answer 2

func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
        let cell = collectionView.dequeueReusableCellWithReuseIdentifier("cell", forIndexPath: indexPath) as! Your_Cell_Class_Name
        cell.configurecell(imagesArray[indexPath.row])
        return cell
}

在cellForItemAt方法中，只需替换 和 ，因为您的代码中没有名为cell的类。

快乐编码

Answer 3

必须在属性检查器中设置标识符。

>

选择属性检查器

提供标识符名称（例如identifier=cell）