swift - 发件人 : UIImageView ! == CollectionViewCell 中的 UIImageView

Question

我正在尝试让 UIImagePicker 在 CollectionViewCell 中显示和成像。 func 代码在 sender 应该等于 (==) 到 UIImageView 的地方被破坏。

我已经多次通过调试器修改代码，并尝试通过 visibleCells 函数调用单元格，但无济于事。

//Code for upload func
@objc func uploadPhoto(_ sender: UIImageView) {
        let uploadPicker = UIImagePickerController()
        uploadPicker.delegate = self
        for cell in self.collectionView.visibleCells {
            if let uploadCell = cell as? UploadImageCell {
                print("Pickle Rick and \(uploadCell.imageContainer) and \(sender)")
                if uploadCell.imageContainer == sender {
                    selectedCell = uploadCell
                    print("This code works, \(String(describing: selectedCell))")
                } else {
                    print("code failed at if let")
                }
            }
        }
        present(uploadPicker, animated: true, completion: nil)
    }

// Code for CollectionView
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(uploadPhoto(_:))))
            return cell
        }
/* other sections use different cells*/
}

//code for CollectionViewCell

class UploadImageCell: UICollectionViewCell {

    // Mark: -  Properties

    weak var ep: EditProfileController?

    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)
        ])

    }

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

}

预期结果是选择器图像显示在 CollectionViewCell.imageContainer 中。我的调试器总是打印“代码在 if let 时失败”，并且 collectionView.reloadData 在 View 加载后从未显示过不同的图像。

Answer 1

点击手势(或任何手势识别器)的选择器必须将实际的手势识别器作为该方法的唯一参数。所以你需要改变:

@objc func uploadPhoto(_ sender: UIImageView) {

到:

@objc func uploadPhoto(_ sender: UITapGestureRecognizer) {

然后您可以从手势的 view 属性中获取 ImageView 。

@objc func uploadPhoto(_ sender: UITapGestureRecognizer) {
    guard let imageView = sender.view as? UIImageView { else return }

    let uploadPicker = UIImagePickerController()
    uploadPicker.delegate = self
    for cell in self.collectionView.visibleCells {
        if let uploadCell = cell as? UploadImageCell {
            print("Pickle Rick and \(uploadCell.imageContainer) and \(sender)")
            if uploadCell.imageContainer == imageView {
                selectedCell = uploadCell
                print("This code works, \(String(describing: selectedCell))")
            } else {
                print("code failed at if let")
            }
        }
    }
    present(uploadPicker, animated: true, completion: nil)
}