ios - 如何结束开关盒

Question

我创建了一个包含随机问题的类，但是 switch 语句没有结束，问题继续循环。如何防止这种情况发生并在随机完成所有 4 个问题后显示另一个页面？

import UIKit

class ThirdViewController: UIViewController {


@IBOutlet weak var Question: UILabel!
@IBOutlet weak var Ans1: UIButton!
@IBOutlet weak var Ans2: UIButton!
@IBOutlet weak var Ans3: UIButton!
@IBOutlet weak var Ans4: UIButton!
@IBOutlet weak var Result: UILabel!
@IBOutlet weak var Next: UIButton!
var correctAns = String()

override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view, typically from a nib.

    Hide()
    Random()
}

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

func Random(){
    var RandomNumber = arc4random() % 4
    RandomNumber += 1

    switch (RandomNumber) {
    case 1:
        Question.text = "Where does minal lives?"
        Ans1.setTitle("dubai", for: UIControlState.normal)
        Ans2.setTitle("london", for: UIControlState.normal)
        Ans3.setTitle("india", for: UIControlState.normal)
        Ans4.setTitle("japan", for: UIControlState.normal)
        correctAns = "2"
        break
    case 2:
        Question.text = "What is my name?"
        Ans1.setTitle("Sunil", for: UIControlState.normal)
        Ans2.setTitle("Harish", for: UIControlState.normal)
        Ans3.setTitle("Rohit", for: UIControlState.normal)
        Ans4.setTitle("Minal", for: UIControlState.normal)
        correctAns = "4"
        break
    case 3:
        Question.text = "How old are you?"
        Ans1.setTitle("22", for: UIControlState.normal)
        Ans2.setTitle("32", for: UIControlState.normal)
        Ans3.setTitle("21", for: UIControlState.normal)
        Ans4.setTitle("28", for: UIControlState.normal)
        correctAns = "1"
        break
    case 4:
        Question.text = "What are you studying?"
        Ans1.setTitle("Computer Science", for: UIControlState.normal)
        Ans2.setTitle("Java", for: UIControlState.normal)
        Ans3.setTitle("Bio", for: UIControlState.normal)
        Ans4.setTitle("Business", for: UIControlState.normal)
        correctAns = "3"

        break

    default:
        Result.text = "Finished"
        break


    }

}

func Hide(){
    Result.isHidden = true
    Next.isHidden = true
}

func Unhide(){
    Result.isHidden = false
    Next.isHidden = false
}




@IBAction func Ans1Action(_ sender: Any) {
    Unhide()
    if (correctAns == "1"){
        Result.text = "Correct!"
    }
    else{
        Result.text = "Try Again"
    }
}


@IBAction func Ans2Action(_ sender: Any) {
    Unhide()
    if (correctAns == "2"){
        Result.text = "Correct!"
    }
    else{
        Result.text = "Try Again"
    }
}


@IBAction func Ans3Action(_ sender: Any) {
    Unhide()
    if (correctAns == "3"){
        Result.text = "Correct!"
    }
    else{
        Result.text = "Try Again"
    }
}


@IBAction func Ans4Action(_ sender: Any) {
    Unhide()
    if (correctAns == "4"){
        Result.text = "Correct!"
    }
    else{
        Result.text = "Try Again"
    }
}

@IBAction func NextAction(_ sender: Any) {
    Random()
    Hide()
}

}

Answer 1

您需要记录已提出的问题数量。 switch (RandomNumber) 将始终输入 case 语句之一，因为 RandomNumber 始终在 1...4 范围内.

所以，你需要做的是添加一个实例变量

private var questionCounter = 0

并修改NextAction函数，如下所示:

@IBAction func NextAction(_ sender: Any) {
    questionCounter += 1
    if questionCounter >= 4 {
        Result.text = "Finished"
        // or whatever...
    }
    else {
        Random()
        Hide()
    }
}

请记住，每次执行 arc4random() 时，同一问题可能会出现多次。