Swift中如何通过三个按钮分别选择三张不同图片并赋值到对应UIImageView

问题根源 #

你当前的EasyImagePickerDelegate回调方法没有区分触发选择操作的是哪一个图片选择器实例，只要有图片返回，就会同时给三个图片视图执行赋值操作，所以才会出现任选一张图三个视图同时更新的问题。

可选解决方案 #

方案1：新增临时变量记录目标视图（无需修改自定义Picker代码，改造成本最低） #

1. 先在控制器中新增属性记录当前要赋值的目标图片视图

class EditProfileImagesVC: UIViewController {
    // 新增属性
    private var currentTargetImageView: UIImageView?
    // 原有其他属性保持不变
    private var imagePicker : EasyImagePicker?
    private var imagePicker1 : EasyImagePicker?
    private var imagePicker2 : EasyImagePicker?
    
    @IBOutlet weak var profilePicImage: UIImageView!
    @IBOutlet weak var leftProfilePicImg: UIImageView!
    @IBOutlet weak var rightProfilePicImg: UIImageView!

    // 原有viewDidLoad保持不变
    override func viewDidLoad() {
        super.viewDidLoad()
        imagePicker = EasyImagePicker(presentationController: self, delegate: self)
        imagePicker1 = EasyImagePicker(presentationController: self, delegate: self)
        imagePicker2 = EasyImagePicker(presentationController: self, delegate: self)
    }

2. 修改按钮点击方法，点击时先记录目标视图

@IBAction func profilePicBtn(_ sender: UIButton) {
        currentTargetImageView = profilePicImage
        imagePicker?.present(from: sender, mediaType: .images, onViewController: self)
    }
    
    @IBAction func leftProfileBtn(_ sender: UIButton) {
        currentTargetImageView = leftProfilePicImg
        imagePicker1?.present(from: sender, mediaType: .images, onViewController: self)
    }
    
    @IBAction func rightProfileBtn(_ sender: UIButton) {
        currentTargetImageView = rightProfilePicImg
        imagePicker2?.present(from: sender, mediaType: .images, onViewController: self)
    }
}

3. 重写回调方法，仅给记录的目标视图赋值

extension EditProfileImagesVC : EasyImagePickerDelegate{
    func didSelect(image: UIImage?, video: URL?, fileName: String?) {
        guard let image = image else { return }
        currentTargetImageView?.image = image
        // 赋值完成后置空，避免意外复用
        currentTargetImageView = nil
    }
}

方案2：修改Picker的代理协议，回传当前触发的Picker实例（可扩展性更好） #

1. 先修改EasyImagePickerDelegate协议定义，给回调方法增加picker参数

protocol EasyImagePickerDelegate: AnyObject {
    func didSelect(picker: EasyImagePicker, image: UIImage?, video: URL?, fileName: String?)
}

2. 在EasyImagePicker内部触发代理回调时，将自身实例作为参数传入
3. 修改控制器的回调实现，根据Picker实例判断赋值目标

extension EditProfileImagesVC : EasyImagePickerDelegate{
    func didSelect(picker: EasyImagePicker, image: UIImage?, video: URL?, fileName: String?) {
        guard let image = image else { return }
        // 用===判断实例身份
        switch picker {
        case imagePicker:
            profilePicImage.image = image
        case imagePicker1:
            leftProfilePicImg.image = image
        case imagePicker2:
            rightProfilePicImg.image = image
        default: break
        }
    }
}

内容的提问来源于stack exchange，提问作者User123