如何从插座外部访问按钮的属性 - Swift

Question

我有一个场景显示数组中的一个问题。故事板包括两个按钮，可以转到下一个/上一个问题。我有一种方法可以向持有当前章节问题（Deck）的班级、当前问题和总问题数量询问。这用于更新标题。

我希望能够使用我的 updateTitle() 函数来控制我的两个按钮的启用状态 - 当当前问题是最后一个问题时禁用“下一个”按钮并禁用“上一个”按钮当显示第一个问题时。

我可以在其插座内更改按钮的状态，例如通过使用相关的 if 语句调用 sender.isEnable = false 。但是这样做的问题是，如果用户在按钮被禁用的点旁边单击，单击上一个按钮不会重新启用“下一个”按钮。

最好在 setTitle() 方法中设置按钮的状态？

这是我的课：

class QuestionController: UIViewController {
    // OUTLETS //////
    // Outlet for the 'question' label
    @IBOutlet weak var questionTextView: UITextView!


    // Outlet for the next button
    @IBAction func nextQuestion(_ sender: UIButton) {
        flashcard = deck.getNextCard()
        questionTextView.text = flashcard!.question
        self.updateTitle()

    }

    // Outlet for last button
    @IBAction func lastQuestion(_ sender: UIButton) {
        flashcard = deck.getLastCard()
        questionTextView.text = flashcard!.question
        self.updateTitle()
    }

    // PROPERTIES /////

    var flashcard: Flashcard! // variable to hold current flashcard
    var deck = Deck(chapter: 0) // Defaults to first chapter until set


    // METHODS //////
    // Update the title with progress
    private func updateTitle() {
        let (chapter, question, totalQuestions) = deck.getProgress()
        self.title = "Chapter \(chapter) question \(question) of \(totalQuestions)"

    }

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
        // Holds deck of data
        flashcard = deck.getCurrentCard()
        questionTextView.text = flashcard!.question

        self.updateTitle() // Update the title with progress
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }



    // Prepare flashcard item to be passed to the answer controller before segue
    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
        if let answerController = segue.destination as? AnswerController {
            answerController.flashcard = flashcard
        }
    }

}

Answer 1

取出按钮使用它。像这样：-

class QuestionController: UIViewController {

    @IBOutlet weak var questionTextView: UITextView!
    @IBOutlet weak var btnNext: UIButton!
}

Answer 2

感谢我最终能够创建出口。然后我用下面的 if 语句更新了 updateTitle() 方法，该语句更新了相关点的按钮状态。

//
//  ViewController.swift
//  CISSP Flashcards
//
//  Created by Laurie Hocking on 24/04/2017.
//  Copyright © 2017 sQuidgy labs. All rights reserved.
//

import UIKit

class QuestionController: UIViewController {
    // OUTLETS //////
    // Outlet for the 'question' label
    @IBOutlet weak var questionTextView: UITextView!
    @IBOutlet weak var nextOutlet: UIButton!
    @IBOutlet weak var lastOutlet: UIButton!

    @IBOutlet weak var nextQuestion: UIButton!
    // Outlet for the next button
    @IBAction func nextQuestion(_ sender: UIButton) {
        flashcard = deck.getNextCard()
        questionTextView.text = flashcard!.question
        self.updateTitle()

    }

    // Outlet for last button
    @IBAction func lastQuestion(_ sender: UIButton) {
        flashcard = deck.getLastCard()
        questionTextView.text = flashcard!.question
        self.updateTitle()
    }

    // PROPERTIES /////

    var flashcard: Flashcard! // variable to hold current flashcard
    var deck = Deck(chapter: 0) // Defaults to first chapter until set


    // METHODS //////
    // Update the title with progress
    private func updateTitle() {
        let (chapter, question, totalQuestions) = deck.getProgress()
        self.title = "Chapter \(chapter) question \(question) of \(totalQuestions)"
        if (question == 1) {
            lastOutlet.isEnabled = false
            nextOutlet.isEnabled = true
        } else if (question == totalQuestions) {
            lastOutlet.isEnabled = true
            nextOutlet.isEnabled = false
        } else {
            lastOutlet.isEnabled = true
            nextOutlet.isEnabled = true
        }

    }

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
        // Holds deck of data
        flashcard = deck.getCurrentCard()
        questionTextView.text = flashcard!.question

        self.updateTitle() // Update the title with progress
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }



    // Prepare flashcard item to be passed to the answer controller before segue
    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
        if let answerController = segue.destination as? AnswerController {
            answerController.flashcard = flashcard
        }
    }

}