swift - 需要帮助使用 CollectionView 单元格显示从 UIImagePicker 上传到 ImageView 的图像

Question

在 Xcode 中构建一个应用程序，我试图将 UIImageView 的图像更改为从 ImagePicker 中选择的图像。我正在处理属于 UICollectionView 中可重用单元格的 ImageView。除了更改实际图像之外，所有代码都有效。

我尝试通过相应的 View Controller 运行代码，尝试将代码添加到 UICollectionViewCell 的类中，并尝试重新加载 Collection View 的数据。

//image picker code
@objc func uploadPhoto(_ sender: UIImageView) {
        let uploadPicker = UIImagePickerController()
        uploadPicker.delegate = self
        present(uploadPicker, animated: true, completion: nil)
    }

    func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {
        var selectedImageFromPicker: UIImage?
        if let originalImage = info[UIImagePickerController.InfoKey.originalImage] as? UIImage {
            selectedImageFromPicker = originalImage
            print("The photo is \(originalImage)")
        }
        if let selectedImage = selectedImageFromPicker {
            let cell = UploadImageCell()
            cell.imageContainer.image = selectedImage
            print("Thumbs Up!!")
            collectionView.reloadData()
        }
        dismissView()
    }

// CollectionView Code:

func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {

        if indexPath.section == 0 {
            let cell = collectionView.dequeueReusableCell(withReuseIdentifier: imageCellId, for: indexPath) as! UploadImageCell
            let imageOption = ImageOption(rawValue: indexPath.row)
            cell.imageContainer.image = imageOption?.icon()
            cell.imageContainer.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(cell.uploadPhoto(_:))))
            return cell
        }
        /* other sections use different cells*/
}


//CollectionViewCell Code:

class UploadImageCell: UICollectionViewCell {

    // Mark: -  Properties

    let imageContainer: UIImageView = {
        let imageContainer = UIImageView()
        imageContainer.clipsToBounds = true
        imageContainer.backgroundColor = .blue
        imageContainer.isUserInteractionEnabled = true
        imageContainer.translatesAutoresizingMaskIntoConstraints = false
        return imageContainer
    }()

    let uploadButton: UIButton = {
        let button = UIButton()
        button.setTitle("Upload Image", for: .normal)
        button.backgroundColor = UIColor.red
        button.setTitleColor(.black, for: .normal)
        button.layer.cornerRadius = 5
        button.layer.shadowColor = UIColor.darkGray.cgColor
        button.layer.shadowOffset = CGSize(width: button.frame.width, height: 2)
        button.layer.shadowRadius = 5
        button.layer.shadowOpacity = 1.0
        button.translatesAutoresizingMaskIntoConstraints = false
        return button
    }()

    override init(frame: CGRect) {
        super.init(frame: frame)
        backgroundColor = .white

        addSubview(imageContainer)
        NSLayoutConstraint.activate([
                imageContainer.topAnchor.constraint(equalTo: topAnchor),
                imageContainer.heightAnchor.constraint(equalTo: heightAnchor, multiplier: 0.9),
                imageContainer.widthAnchor.constraint(equalTo: widthAnchor)
        ])

        addSubview(uploadButton)
        NSLayoutConstraint.activate([
            uploadButton.topAnchor.constraint(equalTo: imageContainer.bottomAnchor, constant: 5),
            uploadButton.centerXAnchor.constraint(equalTo: centerXAnchor),
            uploadButton.widthAnchor.constraint(equalToConstant: 200),
            uploadButton.heightAnchor.constraint(equalToConstant: 30)
            ])
    }

    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

}

期望 imageContainer.image 的输出为“selectedImage”的值

Answer 1

您需要从 collectionView 加载单元，而不是创建新单元

var selectedCell: UploadImageCell?
@objc func uploadPhoto(_ sender: UIImageView) {
        let uploadPicker = UIImagePickerController()
        uploadPicker.delegate = self
        // Get selected cell
        for cell  in self.collectionView.visibleCells {
            if let uploadCell = cell as? UploadImageCell {
                if uploadCell.imageContainer == sender {
                     selectedCell = uploadCell
                }
            }
        }

        present(uploadPicker, animated: true, completion: nil)
    }

    func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {
        var selectedImageFromPicker: UIImage?
        if let originalImage = info[UIImagePickerController.InfoKey.originalImage] as? UIImage {
            selectedImageFromPicker = originalImage
            print("The photo is \(originalImage)")
        }
        // Use selectedcell
        if let selectedImage = selectedImageFromPicker, let cell = selectedCell {
            cell.imageContainer.image = selectedImage
            print("Thumbs Up!!")
            collectionView.reloadData()
        }
        dismissView()
    }