UITapGestureRecognizer 没有附加动作

如何解决UITapGestureRecognizer 没有附加动作

我为 View 创建了一个单独的类。 我把所有的功能都留在了控制器中。 但是当我在图片上添加一个点击时，它由于某种原因不起作用。

False
False
True
['__annotations__','__class__','__dataclass_fields__','__dataclass_params__','__delattr__','__dict__','__dir__','__doc__','__eq__','__format__','__ge__','__getattribute__','__gt__','__hash__','__init__','__init_subclass__','__le__','__lt__','__module__','__ne__','__new__','__reduce__','__reduce_ex__','__repr__','__setattr__','__sizeof__','__str__','__subclasshook__','__weakref__']

import UIKit

class APOTDView: UIView {

    var imageView: UIImageView = {
        let imageView = UIImageView()
        imageView.translatesAutoresizingMaskIntoConstraints = false
        imageView.isUserInteractionEnabled = true
        let tap = UITapGestureRecognizer(target: self,action: #selector(APOTDViewController.imageTapped(_:)))
        imageView.addGestureRecognizer(tap)

        return imageView
    }()
}

怎么了？请帮我弄清楚

解决方法

您在 UITapGestureRecognizer 中的选择器是错误的。不能直接调用APOTDViewController。
APOTDViewController.imageTapped 将是一个静态函数，该函数不可用。

您可以改用委托。

委托协议和视图。

protocol APOTDViewDelegate: AnyObject {
    func viewDidTapImage()
}

class APOTDView: UIView {
    weak var delegate: APOTDViewDelegate?

    var imageView: UIImageView = {
        let imageView = UIImageView()
        imageView.translatesAutoresizingMaskIntoConstraints = false
        imageView.isUserInteractionEnabled = true
        let tap = UITapGestureRecognizer(target: self,action: #selector(imageTapped))
        imageView.addGestureRecognizer(tap)

        return imageView
    }()

    @objc func imageTapped() {
        delegate?.viewDidTapImage()
    }
}

视图控制器：

class APOTDViewController: UIViewController,APOTDViewDelegate {
    let av = APOTDView()

    override func viewDidLoad() {
        super.viewDidLoad()
        av.delegate = self
        // ... add subview and constraint
    }

    @objc func viewDidTapImage() {
        print("good job")
    }
}

,

这行不通，因为您在没有任何类引用或对象的情况下直接调用 UIViewController 方法。解决方案是使用协议或clouser 来获取从视图到类的操作。

类

class APOTDView: UIView {
    @objc var imageViewAction: ((UITapGestureRecognizer) -> Void)? = nil
    
    lazy var imageView: UIImageView = {
        let imageView = UIImageView()
        imageView.backgroundColor = .blue
        imageView.translatesAutoresizingMaskIntoConstraints = true
        imageView.isUserInteractionEnabled = true
        let tap = UITapGestureRecognizer(target: self,action: #selector((imageTapped(_:))))
        imageView.addGestureRecognizer(tap)
        return imageView
    }()
    
    @objc private func imageTapped(_ sender: UITapGestureRecognizer) {
        self.imageViewAction?(sender)
    }
}

视图控制器

class APOTDViewController: UIViewController {
    let av = APOTDView()

    override func viewDidLoad() {
        super.viewDidLoad()
        av.imageViewAction = { sender in
            print("good job")
        }
    }
}