ios - 闭包内的自实例

Question

我在尝试设置动画并更改闭包内 ui 元素的某些属性时遇到问题。当我尝试通过函数对某些 View 进行动画处理时，它执行该函数但动画无法完成，但是当我在闭包之外执行该函数时，它工作正常。这是我的代码，我的问题出在 AuthController 底部的委托(delegate)扩展中，函数名为 facebookAuth。我已经苦苦挣扎了将近一天了，我找不到错误。

我在动画和函数中放置了一些打印语句来追踪目的，这些是执行的语句:

Login successful (this one is in the delegate function

slide (this one is in the slide function)

not complete (this one is in the animation closure)

AuthController

import UIKit
import AVFoundation
import FBSDKLoginKit
import FBSDKCoreKit
import Firebase

protocol AuthControllerDelegate {
    func login(withUser user: User)
    func facebookAuth()
    func signUp(withUser user: User)
    func facebookRegister(withEmail email: String, cellphone: String)
}

class AuthController: UIViewController {
    
    enum AuthView {
        case registerView
        case loginView
        case fbRegisterSecondStepCenter
    }
    
    private var player: AVPlayer!
    private var playerLayer: AVPlayerLayer!
    private var registerViewCenterConstraint: NSLayoutConstraint?
    private var loginViewCenterConstraint: NSLayoutConstraint?
    private var fbRegisterSecondStepCenterConstraint: NSLayoutConstraint?
    private var currentView: AuthView = .loginView
    private var facebookUserStore: User?
    
    override var preferredStatusBarStyle: UIStatusBarStyle {
        return .lightContent
    }
    
    override var supportedInterfaceOrientations: UIInterfaceOrientationMask {
        return .portrait
    }
    
    private let purpleBackground: UIView = {
        let pb = UIView()
        pb.backgroundColor = .darkBackground
        pb.alpha = 0.5
        return pb
    }()
    
    //MARK: AuthViews
    
    private lazy var loginView: LoginView = {
        let view = LoginView()
        view.delegate = self
        return view
    }()
    
    private lazy var registerView: RegisterView = {
        let view = RegisterView()
//        view.delegate = self
        view.alpha = 0
        return view
    }()
    
    private lazy var fbRegisterSecondStep: FBRegisterSecondStep = {
        let view = FBRegisterSecondStep()
        view.alpha = 0
        view.delegate = self
        return view
    }()
    
    private lazy var bottomBtn: UIButton = {
        let btn = UIButton()
        let attributedString = NSMutableAttributedString(string: "Not registered? Sign up.", attributes: [.foregroundColor: UIColor.lightText, .font: UIFont.init(name: Fonts.lightFont.rawValue, size: 16)!])
        btn.setAttributedTitle(attributedString, for: .normal)
        btn.contentHorizontalAlignment = .center
        btn.addTarget(self, action: #selector(handleChangeView), for: .touchUpInside)
        return btn
    }()
    
    let alertController: AlertController = {
        let ac = AlertController()
        return ac
    }()

    override func viewDidLoad() {
        super.viewDidLoad()
        print(UserDefaults.Account.bool(forKey: .isUserLoggedIn))
        setVideoBackground()
        setupViews()
        alertController.transitioningDelegate = alertController
        alertController.modalPresentationStyle = .custom
    }
    
    override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)
        navigationController?.isNavigationBarHidden = true
    }
    
    override func viewWillDisappear(_ animated: Bool) {
        super.viewWillAppear(animated)
        navigationController?.isNavigationBarHidden = false
    }
    
    private func setupViews() {
        view.addSubview(purpleBackground)
        view.addSubview(loginView)
        view.addSubview(registerView)
        view.addSubview(fbRegisterSecondStep)
        view.addSubview(bottomBtn)
        
        _ = purpleBackground.anchor(top: view.topAnchor, bottom: view.bottomAnchor, right: view.rightAnchor, left: view.leftAnchor)
        
        loginViewCenterConstraint = loginView.centerInView().first
        _ = loginView.anchorWithMultiplier(top: nil, bottom: nil, right: nil, left: nil, height: view.heightAnchor, width: view.widthAnchor, topConstant: 0, bottomConstant: 0, rightConstant: 0, leftConstant: 0, widthMultiplier: 0.8, heightMultiplier: 0.6)
        
        registerViewCenterConstraint = registerView.centerInView().first
        registerViewCenterConstraint?.constant = 1000
        _ = registerView.anchorWithMultiplier(top: nil, bottom: nil, right: nil, left: nil, height: view.heightAnchor, width: view.widthAnchor, topConstant: 0, bottomConstant: 0, rightConstant: 0, leftConstant: 0, widthMultiplier: 0.8, heightMultiplier: 0.8)
        
        fbRegisterSecondStepCenterConstraint = fbRegisterSecondStep.centerInView().first
        fbRegisterSecondStepCenterConstraint?.constant = 1000
        _ = fbRegisterSecondStep.anchorWithMultiplier(top: nil, bottom: nil, right: nil, left: nil, height: view.heightAnchor, width: view.widthAnchor, topConstant: 0, bottomConstant: 0, rightConstant: 0, leftConstant: 0, widthMultiplier: 0.8, heightMultiplier: 0.5)
        
        _ = bottomBtn.anchor(top: nil, bottom: view.bottomAnchor, right: view.rightAnchor, left: view.leftAnchor, topConstant: 0, bottomConstant: 20, rightConstant: 0, leftConstant: 0, widthConstant: 0, heightConstant: 0)
    }
    
    private func setVideoBackground() {
        let videoPath = Bundle.main.url(forResource: "trim720", withExtension: "mp4")
        player = AVPlayer(url: videoPath!)
        playerLayer = AVPlayerLayer(player: player)
        playerLayer.videoGravity = .resizeAspectFill
        playerLayer.frame = view.frame
        player.actionAtItemEnd = .none
        player.play()
        
        view.layer.insertSublayer(playerLayer, at: 0)
        
        NotificationCenter.default.addObserver(self, selector: #selector(handleStop), name: NSNotification.Name.AVPlayerItemDidPlayToEndTime, object: player.currentItem)
    }
    
    private func slide(toView view: AuthView, completion: @escaping (Bool) -> Void = { _ in }) {
        guard let registerCenterConstraint = registerViewCenterConstraint, let loginCenterConstraint = loginViewCenterConstraint, let fbRegisterSecondConstraint = fbRegisterSecondStepCenterConstraint else {
            fatalError("Error unwrapping auth views constraints.")
        }
        switch view {
        case .loginView:
            loginCenterConstraint.constant = 0
            registerCenterConstraint.constant = 1000
            fbRegisterSecondConstraint.constant = 1000
            currentView = .loginView
        case .registerView:
            loginCenterConstraint.constant = 1000
            registerCenterConstraint.constant = 0
            fbRegisterSecondConstraint.constant = 1000
            currentView = .registerView
        case .fbRegisterSecondStepCenter:
            loginCenterConstraint.constant = 1000
            registerCenterConstraint.constant = 1000
            fbRegisterSecondConstraint.constant = 0
            currentView = .fbRegisterSecondStepCenter
            print("slideeeeeeeeeeee")
        }
        let isRegisterVisible = registerCenterConstraint.constant == 0
        let isLoginVisible = loginCenterConstraint.constant == 0
        let isFbRegisterVisible = fbRegisterSecondConstraint.constant == 0
        
        UIView.animate(withDuration: 0.5, delay: 0, usingSpringWithDamping: 0.8, initialSpringVelocity: 1, options: .curveEaseOut, animations: {
            self.registerView.alpha = isRegisterVisible ? 1 : 0
            self.loginView.alpha = isLoginVisible ? 1 : 0
            self.fbRegisterSecondStep.alpha = isFbRegisterVisible ? 1 : 0
            self.view.layoutIfNeeded()
            print("slide")
        }) { (state) in
            if state {
                print("completed")
            } else {
                print("not completed")
            }
            completion(state)
        }
    }
    
    fileprivate func pushHome() {
        navigationController?.isNavigationBarHidden = false
        navigationController?.setViewControllers([HomeController()], animated: true)
    }
    
    // MARK: Handlers
    
    @objc private func handleStop() {
        player.seek(to: kCMTimeZero)
    }
    
    @objc private func handleChangeView() {
        
        let isLoginVisible = currentView == .loginView
        let view: AuthView = isLoginVisible ? .registerView : .loginView
        slide(toView: view) { (completed) in
            let attributedString = self.bottomBtn.attributedTitle(for: .normal) as! NSMutableAttributedString
            let newTitle = isLoginVisible ? "Already an user? Sign In" : "Not registered? Sign up."
            attributedString.mutableString.setString(newTitle)
        }
    }
}

extension AuthController: Loginable, Registable, AuthControllerDelegate {
    
    func login(withUser user: User) {
        signIn(withUser: user) { (_) in
            self.pushHome()
        }
    }
    
    func facebookAuth(){
        let loginManager = FBSDKLoginManager()
        loginManager.logIn(withReadPermissions: ["email", "public_profile"], from: self) { (result, err) in
            if err == nil, !(result?.isCancelled)!, let token = result?.token.tokenString {
                print("Login successful")
                self.loginView.isHidden = true
                self.bottomBtn.isHidden = true
                self.slide(toView: .registerView)
            }
        }
    }
    
    func facebookRegister(withEmail email: String, cellphone: String) {
        guard let user = facebookUserStore else {
            fatalError("Error linking accounts")
        }
        register(withUser: user) { (completed) in
            if completed {
                self.linkAccount(withEmail: email, cellphone: cellphone, completion: { (completion) in
                    if completion {
                        self.pushHome()
                    }
                })
            }
        }
    }
    
    func signUp(withUser user: User) {
        register(withUser: user) { (_) in
            print("registrado")
            UserDefaults.Account.set(true, forKey: .isUserLoggedIn)
            self.pushHome()
        }
    }
}

当单击 fbButton 时，该函数通过此 View 内的委托(delegate)执行。

登录查看

//
//  LoginView.swift
//  TaxiApp
//
//  Created by Leonardo Dominguez on 10/2/17.
//  Copyright © 2017 Leonardo Dominguez. All rights reserved.
//

import UIKit

class LoginView: BaseView {
    
    var delegate: AuthControllerDelegate?
    
    private let emailField: TAField = {
        let pf = TAField(placeHolder: "E-mail", keyboardType: .emailAddress)
        return pf
    }()
    
    private let passwordField: TAField = {
        let pf = TAField(placeHolder: "Password")
        pf.isSecureTextEntry = true
        return pf
    }()
    
    private lazy var loginBtn: TAButton = {
        let btn = TAButton(title: "Login")
        btn.addTarget(self, action: #selector(handleLogin), for: .touchUpInside)
        return btn
    }()
    
    private let facebookBtn: TAButton = {
        let btn = TAButton()
        btn.backgroundColor = UIColor(hexString: "#3b5998")
        btn.setAttributedTitle(NSAttributedString(string: "Login with Facebook", attributes: [.foregroundColor: UIColor.lightText, .font: UIFont.init(name: Fonts.mediumFont.rawValue, size: 20)!]), for: .normal)
        return btn
    }()
    
    private let forgotPassword: UIButton = {
        let btn = UIButton()
        btn.setAttributedTitle(NSAttributedString(string: "Forgot password", attributes: [.foregroundColor: UIColor.placeholderText, .font: UIFont.init(name: Fonts.mediumFont.rawValue, size: 16)!]), for: .normal)
        btn.contentHorizontalAlignment = .right
        return btn
    }()
    
    private let orView: UIView = {
        let container = UIView()
        let lbl = UILabel()
        lbl.text = "or"
        lbl.textColor = .lightText
        lbl.font = UIFont(name: Fonts.mediumFont.rawValue, size: 20)
        let leftLine = UIView()
        let rightLine = UIView()
        leftLine.backgroundColor = .lightLine
        rightLine.backgroundColor = .lightLine
        container.addSubview(rightLine)
        container.addSubview(lbl)
        container.addSubview(leftLine)
        rightLine.centerYAnchor.constraint(equalTo: container.centerYAnchor).isActive = true
        _ = rightLine.anchor(top: nil, bottom: nil, right: container.rightAnchor, left: lbl.rightAnchor, topConstant: 0, bottomConstant: 0, rightConstant: 70, leftConstant: 3, widthConstant: 0, heightConstant: 1.0)
        _ = lbl.centerInView()
        leftLine.centerYAnchor.constraint(equalTo: container.centerYAnchor).isActive = true
        _ = leftLine.anchor(top: nil, bottom: nil, right: lbl.leftAnchor, left: container.leftAnchor, topConstant: 0, bottomConstant: 0, rightConstant: 3, leftConstant: 70, widthConstant: 0, heightConstant: 1.0)
        return container
    }()
    
    override func setupViews() {
        setupBtns()
        
        addSubview(emailField)
        addSubview(passwordField)
        addSubview(forgotPassword)
        addSubview(loginBtn)
        addSubview(orView)
        addSubview(facebookBtn)
        
        _ = emailField.anchor(top: topAnchor, bottom: nil, right: rightAnchor, left: leftAnchor, topConstant: 20, bottomConstant: 0, rightConstant: 0, leftConstant: 0, widthConstant: 0, heightConstant: Theme.fieldHeight)
        
        _ = passwordField.anchorWithMultiplier(top: emailField.bottomAnchor, bottom: nil, right: emailField.rightAnchor, left: emailField.leftAnchor, height: emailField.heightAnchor, width: nil, topConstant: Theme.topPadding, bottomConstant: 0, rightConstant: 0, leftConstant: 0, widthMultiplier: 0, heightMultiplier: 1)
        
        _ = forgotPassword.anchor(top: passwordField.bottomAnchor, bottom: nil, right: emailField.rightAnchor, left: emailField.leftAnchor, topConstant: 5, bottomConstant: 0, rightConstant: 0, leftConstant: 0, widthConstant: 0, heightConstant: 0)
        
        _ = loginBtn.anchorWithMultiplier(top: passwordField.bottomAnchor, bottom: nil, right: emailField.rightAnchor, left: emailField.leftAnchor, height: emailField.heightAnchor, width: nil, topConstant: Theme.topPadding, bottomConstant: 0, rightConstant: 0, leftConstant: 0, widthMultiplier: 0, heightMultiplier: 1)
        
        _ = orView.anchor(top: loginBtn.bottomAnchor, bottom: nil, right: rightAnchor, left: leftAnchor, topConstant: Theme.topPadding / 2, bottomConstant: 0, rightConstant: 0, leftConstant: 0, widthConstant: 0, heightConstant: 10)
        
        _ = facebookBtn.anchorWithMultiplier(top: orView.bottomAnchor, bottom: nil, right: emailField.rightAnchor, left: emailField.leftAnchor, height: emailField.heightAnchor, width: nil, topConstant: Theme.topPadding / 2, bottomConstant: 0, rightConstant: 0, leftConstant: 0, widthMultiplier: 0, heightMultiplier: 1)
        
    }
    
    func setupBtns() {
        facebookBtn.addTarget(self, action: #selector(handleFacebookLogin), for: .touchUpInside)
    }
    
    @objc func handleFacebookLogin() {
        delegate?.facebookAuth()
    }
    
    @objc func handleLogin() {
        if let email = emailField.text, let password = passwordField.text {
            let user = User(email: email, password: password)
            delegate?.login(withUser: user)
        }
    }

}

更新

因此，在很多人尝试整个应用程序之后，我只注意到错误属于 RouterController，它是嵌入了 AuthController 的 UINavigationController 子类。当我更改 Windows rootviewcontroller 以避免 RouterController 并直接转到 AuthController 时，一切都开始工作。现在我的疑问是，为什么会发生这种情况？我试图弄清楚，这样我就可以修复或在将来的情况下，但我不知道为什么，这是我的代码:

路由器 Controller

import UIKit

class RouterController: UINavigationController {
    
    override func viewDidLoad() {
        super.viewDidLoad()
//        perform(#selector(redirect), with: nil, afterDelay: 0)
    }
    
    override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)
        redirect()
    }
    
    @objc func redirect() {
        if UserDefaults.Account.bool(forKey: .isUserLoggedIn) {
            viewControllers = [HomeController()]
        } else {
            setViewControllers([AuthController()], animated: false)
        }
    }
}

Answer 1

尝试在主线程上执行闭包中的所有内容，如下所示:

func facebookAuth(){
    let loginManager = FBSDKLoginManager()
    loginManager.logIn(withReadPermissions: ["email", "public_profile"], from: self) {[weak self] (result, err) in
        if err == nil, !(result?.isCancelled)!, let token = result?.token.tokenString {
            print("Login successful")
            DispatchQueue.main.async {
                self?.loginView.isHidden = true
                self?.bottomBtn.isHidden = true
                self?.slide(toView: .registerView)
            }
        }
    }
}