分段控制在段0

Question

我有一个分段控件，可以在我的一个View Controllers上改变5个图像（见下图），但是当有人进入Casting选项卡时，我希望立即选择Segment 0。目前只有当我进入第1段或第2段然后回来时它才被选中，之后它显然可以正常工作。

在行为我已启用并选中的属性检查器中，我甚至尝试过选中状态，但总是相同的结果，所以我不确定我哪里出错了。我可以通过向我的ViewDidLoad添加5个图像的代码来获得视觉修复，将其中的四个设置为.isHidden = true，将其中一个设置为.isHidden = false，但这显然无法解决我的问题。

这是我的代码：

    import UIKit

        class CastingViewController: UIViewController {

            let runesArray = [Rune(runeName: "Fehu", runeImage: UIImage(named: ("Fehu.png"))!, runeDescription: "Description goes here."),
                              Rune(runeName: "Uruz", runeImage: UIImage(named: ("Uruz.png"))!, runeDescription: "Description goes here."),
                              Rune(runeName: "Thurisaz", runeImage: UIImage(named: ("Thurisaz.png"))!, runeDescription: "Description goes here."),
                              Rune(runeName: "Ansuz", runeImage: UIImage(named: ("Ansuz.png"))!, runeDescription: "Description goes here."),
                              Rune(runeName: "Raidho", runeImage: UIImage(named: ("Raidho.png"))!, runeDescription: "Description goes here."),
                              Rune(runeName: "Kenaz", runeImage: UIImage(named: ("Kenaz.png"))!, runeDescription: "Description goes here."),
                              Rune(runeName: "Gebo", runeImage: UIImage(named: ("Gebo.png"))!, runeDescription: "Description goes here."),
                              Rune(runeName: "Wunjo", runeImage: UIImage(named: ("Wunjo.png"))!, runeDescription: "Description goes here."),

                              Rune(runeName: "Hagalaz", runeImage: UIImage(named: ("Hagalaz.png"))!, runeDescription: "Description goes here."),
                              Rune(runeName: "Nauthiz", runeImage: UIImage(named: ("Nauthiz.png"))!, runeDescription: "Description goes here."),
                              Rune(runeName: "Isa", runeImage: UIImage(named: ("Isa.png"))!, runeDescription: "Description goes here."),
                              Rune(runeName: "Jera", runeImage: UIImage(named: ("Jera.png"))!, runeDescription: "Description goes here."),
                              Rune(runeName: "Eihwaz", runeImage: UIImage(named: ("Eihwaz.png"))!, runeDescription: "Description goes here."),
                              Rune(runeName: "Perthro", runeImage: UIImage(named: ("Perthro.png"))!, runeDescription: "Description goes here."),
                              Rune(runeName: "Algiz", runeImage: UIImage(named: ("Algiz.png"))!, runeDescription: "Description goes here."),
                              Rune(runeName: "Sowilo", runeImage: UIImage(named: ("Sowilo.png"))!, runeDescription: "Description goes here."),

                              Rune(runeName: "Tiwaz", runeImage: UIImage(named: ("Tiwaz.png"))!, runeDescription: "Description goes here."),
                              Rune(runeName: "Berkano", runeImage: UIImage(named: ("Berkano.png"))!, runeDescription: "Description goes here."),
                              Rune(runeName: "Ehwaz", runeImage: UIImage(named: ("Ehwaz.png"))!, runeDescription: "(Description goes here."),
                              Rune(runeName: "Mannaz", runeImage: UIImage(named: ("Mannaz.png"))!, runeDescription: "Description goes here."),
                              Rune(runeName: "Laguz", runeImage: UIImage(named: ("Laguz.png"))!, runeDescription: "Description goes here."),
                              Rune(runeName: "Ingwaz", runeImage: UIImage(named: ("Ingwaz.png"))!, runeDescription: "Description goes here."),
                              Rune(runeName: "Dagaz", runeImage: UIImage(named: ("Dagaz.png"))!, runeDescription: "Description goes here."),
                              Rune(runeName: "Othala", runeImage: UIImage(named: ("Othala.png"))!, runeDescription: "Description goes here.")]

            var runesCastArray: [UIImage] = [] // Array to save Rune images for 3 or 5 Rune Cast

    @IBOutlet weak var segmentedControl: UISegmentedControl!
    @IBOutlet weak var runeOne: UIImageView!
    @IBOutlet weak var runeTwo: UIImageView!
    @IBOutlet weak var runeThree: UIImageView!
    @IBOutlet weak var runeFour: UIImageView!
    @IBOutlet weak var runeFive: UIImageView!

    override func viewDidLoad() {
        super.viewDidLoad()

        // Do any additional setup after loading the view.

    }

    override func viewWillAppear(_ animated: Bool) {
        segmentedControl.selectedSegmentIndex = 0
    }

    var runeCast = 0 // Need to check if this will work in a Switch statement

    var storedRuneOne: UIImage!
    var storedRuneTwo: UIImage!
    var storedRuneThree: UIImage!
    var storedRuneFour: UIImage!
    var storedRuneFive: UIImage!

    func oneRuneCast() {

        runeCast = 1
        runeOne.isHidden = true
        runeTwo.isHidden = true
        runeThree.isHidden = true
        runeFour.isHidden = true
        runeFive.isHidden = false

    }

    func threeRuneCast() {

        runeCast = 3
        runeOne.isHidden = true
        runeTwo.isHidden = false
        runeThree.isHidden = true
        runeFour.isHidden = false
        runeFive.isHidden = false

    }

    func fiveRuneCast() {

        runeCast = 5
        runeOne.isHidden = false
        runeTwo.isHidden = false
        runeThree.isHidden = false
        runeFour.isHidden = false
        runeFive.isHidden = false

    }

    @IBAction func castType(_ sender: Any) {

       switch segmentedControl.selectedSegmentIndex {
        case 0:
            oneRuneCast()
        case 1:
            threeRuneCast()
        case 2:
            fiveRuneCast()
        default: break
        }

    }

    @IBAction func castButtonPressed(_ sender: Any) {

        if runeCast == 1 {

        let randomRunes = runesArray[Int(arc4random_uniform(UInt32(runesArray.count)))]

            runeFive.image = randomRunes.runeImage


        } else if runeCast == 3 {

            let randomRunes = runesArray[Int(arc4random_uniform(UInt32(runesArray.count)))]

            runeTwo.image = randomRunes.runeImage
            runeFour.image = randomRunes.runeImage
            runeFive.image = randomRunes.runeImage

        } else if runeCast == 5 {

            let randomRunes = runesArray[Int(arc4random_uniform(UInt32(runesArray.count)))]

            runeOne.image = randomRunes.runeImage
            runeTwo.image = randomRunes.runeImage
            runeThree.image = randomRunes.runeImage
            runeFour.image = randomRunes.runeImage
            runeFive.image = randomRunes.runeImage

            }
    }
}

Answer 1

以编程方式在viewDidAppear或viewDidLoad中设置段索引（达到您的应用程序要求）

override func viewDidAppear() {
        super.viewDidAppear()

        segmentedControl.selectedSegmentIndex = 0
}

Answer 2

您需要在视图出现时重置所选的段索引（例如在viewWillAppear中），但以编程方式更改所选的段不会调用操作处理程序;你需要明确地调用它。

您还可以将UIImageViews放入数组中来简化代码;

class CastingViewController: UIViewController {

            let runesArray = [Rune(runeName: "Fehu", runeImage: UIImage(named: ("Fehu.png"))!, runeDescription: "Description goes here."),
                              Rune(runeName: "Uruz", runeImage: UIImage(named: ("Uruz.png"))!, runeDescription: "Description goes here."),
                              Rune(runeName: "Thurisaz", runeImage: UIImage(named: ("Thurisaz.png"))!, runeDescription: "Description goes here."),
                              Rune(runeName: "Ansuz", runeImage: UIImage(named: ("Ansuz.png"))!, runeDescription: "Description goes here."),
                              Rune(runeName: "Raidho", runeImage: UIImage(named: ("Raidho.png"))!, runeDescription: "Description goes here."),
                              Rune(runeName: "Kenaz", runeImage: UIImage(named: ("Kenaz.png"))!, runeDescription: "Description goes here."),
                              Rune(runeName: "Gebo", runeImage: UIImage(named: ("Gebo.png"))!, runeDescription: "Description goes here."),
                              Rune(runeName: "Wunjo", runeImage: UIImage(named: ("Wunjo.png"))!, runeDescription: "Description goes here."),

                              Rune(runeName: "Hagalaz", runeImage: UIImage(named: ("Hagalaz.png"))!, runeDescription: "Description goes here."),
                              Rune(runeName: "Nauthiz", runeImage: UIImage(named: ("Nauthiz.png"))!, runeDescription: "Description goes here."),
                              Rune(runeName: "Isa", runeImage: UIImage(named: ("Isa.png"))!, runeDescription: "Description goes here."),
                              Rune(runeName: "Jera", runeImage: UIImage(named: ("Jera.png"))!, runeDescription: "Description goes here."),
                              Rune(runeName: "Eihwaz", runeImage: UIImage(named: ("Eihwaz.png"))!, runeDescription: "Description goes here."),
                              Rune(runeName: "Perthro", runeImage: UIImage(named: ("Perthro.png"))!, runeDescription: "Description goes here."),
                              Rune(runeName: "Algiz", runeImage: UIImage(named: ("Algiz.png"))!, runeDescription: "Description goes here."),
                              Rune(runeName: "Sowilo", runeImage: UIImage(named: ("Sowilo.png"))!, runeDescription: "Description goes here."),

                              Rune(runeName: "Tiwaz", runeImage: UIImage(named: ("Tiwaz.png"))!, runeDescription: "Description goes here."),
                              Rune(runeName: "Berkano", runeImage: UIImage(named: ("Berkano.png"))!, runeDescription: "Description goes here."),
                              Rune(runeName: "Ehwaz", runeImage: UIImage(named: ("Ehwaz.png"))!, runeDescription: "(Description goes here."),
                              Rune(runeName: "Mannaz", runeImage: UIImage(named: ("Mannaz.png"))!, runeDescription: "Description goes here."),
                              Rune(runeName: "Laguz", runeImage: UIImage(named: ("Laguz.png"))!, runeDescription: "Description goes here."),
                              Rune(runeName: "Ingwaz", runeImage: UIImage(named: ("Ingwaz.png"))!, runeDescription: "Description goes here."),
                              Rune(runeName: "Dagaz", runeImage: UIImage(named: ("Dagaz.png"))!, runeDescription: "Description goes here."),
                              Rune(runeName: "Othala", runeImage: UIImage(named: ("Othala.png"))!, runeDescription: "Description goes here.")]

            var runesCastArray: [UIImage] = [] // Array to save Rune images for 3 or 5 Rune Cast

    @IBOutlet weak var segmentedControl: UISegmentedControl!
    @IBOutlet weak var runeOne: UIImageView!
    @IBOutlet weak var runeTwo: UIImageView!
    @IBOutlet weak var runeThree: UIImageView!
    @IBOutlet weak var runeFour: UIImageView!
    @IBOutlet weak var runeFive: UIImageView!

    var runeImageViews:[UIImageView]!
    var runeCount = 1

    override func viewDidLoad() {
        super.viewDidLoad()

        // Do any additional setup after loading the view.

        self.runeImageViews=[runeFive,runeFour,runeThree,runeTwo,runeOne]

    }

    override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)
        segmentedControl.selectedSegmentIndex = 0
        self.runeCount = 1
        self.showHideRuneViews()
    }

    func showHideRuneViews(clearImage: Bool=true) {
        for i in 0..<self.runeImageViews.count {
            let imageView = self.runeImageViews[i]
            if i < self.runeCount {
                imageView.isHidden = false
            } else {
                imageView.isHidden = true
            }
            if clearImage {
                imageView.image = nil
            }
        }
    }

    func runeCast() {
        for i in 0..<self.runeImageViews.count.reversed() {
            let imageView = self.runeImageViews[i]
            if i < self.runeCount {
                 imageView.image = runesArray[Int(arc4random_uniform(UInt32(runesArray.count)))]
            } else {
                  imageView.image = nil
        }
    }

    @IBAction func castType(_ sender: Any) {

       switch segmentedControl.selectedSegmentIndex {
        case 0:
            self.runeCount = 1
        case 1:
            self.runeCount = 3
        case 2:
            self.runeCount = 5
        default: break
        }

        self.showHideRuneViews()

    }

    @IBAction func castButtonPressed(_ sender: Any) {
        self.runeCast()
    }
}