ios - UIButton 按下不会调用函数

Question

我是 swift 的新手，创建了一个 viewcontroller 和一个 mainView.swift，它包含所有样式和 ui 元素，但是 mainView.swift 中的按钮没有调用我创建的函数，我应该添加所有元素在它们加载后加载正常，我点击登录按钮没有任何反应，我对 swift 中的 View 层次结构进行了一些研究，但注意到帮助解决了问题，任何帮助将不胜感激

主视图.swift

import Foundation
import UIKit
import PureLayout

class login: UIView {
var shouldSetupConstraints = true



var logoImageContainer = UIView()
var logoImage = UIImageView(image: UIImage(named: "logo"))
var loginButton = UIButton()
var registerButton = UIButton()

let screenSize = UIScreen.main.bounds
let gradient = CAGradientLayer()


override init(frame: CGRect) {
    super.init(frame: frame)

    logoImage.center = CGPoint(x: screenSize.width/2, y:0)
    logoImage.alpha = 0.0

    self.addSubview(logoImage)

    loginButton.frame = CGRect(x: screenSize.width/14, y: screenSize.height/1.35, width: 320, height: 50)
    gradient.frame = loginButton.bounds
    gradient.colors = [UIColor(red: (0/255.0), green: (114/255.0), blue: (255/255.0), alpha: 1).cgColor , UIColor(red: (0/255.0), green: (198/255.0), blue: (255/255.0), alpha: 1).cgColor]
    gradient.startPoint = CGPoint(x: 0, y: 0)
    gradient.endPoint = CGPoint(x: 1, y: 0)
    gradient.cornerRadius = 4
    loginButton.layer.addSublayer(gradient)
    loginButton.setTitle("SIGN IN", for: .normal)
    loginButton.titleLabel?.font = UIFont(name: "HelveticaNeue-medium", size: 30)
    loginButton.titleLabel?.textAlignment = .center
    loginButton.alpha = 0.0
    loginButton.addTarget(self, action: #selector(loginPressed), for: .touchUpInside)

    self.addSubview(loginButton)

    registerButton.frame = CGRect(x: screenSize.width/14, y: screenSize.height/1.175, width: 320, height: 50)
    registerButton.setTitle("Create Account", for: .normal)
    registerButton.setTitleColor(UIColor.gray, for: UIControlState.normal)
    registerButton.titleLabel?.font = UIFont(name: "HelveticaNeue-medium", size: 24)
    registerButton.titleLabel?.textAlignment = .center
    registerButton.alpha = 0.0

    self.addSubview(registerButton)

    UIView.animate(withDuration: 1.0, animations: { () -> Void in
        self.loginButton.alpha = 1.0
        self.registerButton.alpha = 1.0
        self.logoImage.alpha = 1.0
        self.logoImage.center = CGPoint(x: self.screenSize.width/2, y:self.screenSize.height/2.5)
    })



}

@objc func loginPressed() {
    print("press")
    /* UIView.animate(withDuration: 1.0, animations: { () -> Void in
     self.loginButton.center = CGPoint(x: self.screenSize.width/14, y: self.screenSize.height/1.175)
     self.registerButton.alpha = 0.0
     self.registerButton.center = CGPoint(x: self.screenSize.width/2, y:self.screenSize.height/1)
     self.logoImage.center = CGPoint(x: self.screenSize.width/2, y:self.screenSize.height/1.5)
     }) */
}

required init?(coder aDecoder: NSCoder) {
    super.init(coder: aDecoder)
}

override func updateConstraints() {
    if(shouldSetupConstraints) {
        // AutoLayout constraints
        shouldSetupConstraints = false
    }
    super.updateConstraints()
}
}

MainViewController.swift

class MainViewController: UIViewController {

 var loginView: login!

override func viewDidLoad() {
    super.viewDidLoad()
   self.view.backgroundColor = UIColor(red: (255/255.0), green: (255/255.0), blue: (255/255.0), alpha: 1)
    loginView = login()
    loginView.isUserInteractionEnabled = true
    self.view.addSubview(loginView)
}
}

Answer 1

您代码中的问题是您的 loginPressed 方法缺少一个参数。单击按钮时，它将调用您的方法，并且作为参数，它会将单击的按钮对象发送到您的方法。

但是正在调用的方法的签名与您的 loginPressed 方法不匹配。应该是这样的

@objc func loginPressed(sender: UIButton!) {  
          print("login Clicked")  
     }