我正在尝试学习 UISegmentedControl 并想弄清楚如何让它在 if 语句中工作以根据选择返回一个值并根据其他选择返回另一个值。 UISegment 只能返回两个值——“Fixed”或“Varibale”。下面的代码不起作用，但给出了我想要的想法。这两个变量是预定义的。

  @IBAction func calPenalty(_ sender: UIButton) {

    let startDate = termStartDate.text
    let mortgageTerm = Double(mortgageTermLabel.text!)
    let discount = Double(mortgageDiscountLabel.text!)
    let mtgCashback = Double(casbackRecieved.text!)
    let mtgBalance = Double(mortgageBalance.text!)
    let rate = Double(currentRate.text!)
    //let mortgageType = mortgageType

    let lender = Global.selectedRate
    if let oneYear = Double((lender?.oneYear)!),
        let twoYear = Double((lender?.twoYear)!),
        let threeYear = Double((lender?.threeYear)!),
        let fourYear = Double((lender?.fourYear)!),
        let fiveYear = Double((lender?.fiveYear)!) {

        let maturityDate = (getMaturityDate(startdate: startDate!, termMonths: Int(mortgageTerm!)))

        let monthsToMaturity = daysBetweenDates(endDate: maturityDate)/365*12

        let comparisonTerm = (IRDComparisonTerm(monthsToMaturity: monthsToMaturity))

        let cashback = cashbackRepayment(cashbackRecieved: mtgCashback!, mtgTerm: Double(mortgageTerm!), mthsToMaturity: Double(monthsToMaturity))

        print(cashback)


        var comparisonRate: Double = 0

        switch comparisonTerm
        {
        case 12:
            comparisonRate = oneYear

        case 24:
            comparisonRate =  twoYear

        case 36:
            comparisonRate =  threeYear
        case 48:
            comparisonRate = fourYear
        case 60:
            comparisonRate = fiveYear

        default:
            comparisonRate = 0

        } // end switch statement

       print(comparisonRate)

        let IRD = IRDPenalty(IRDComparisonRate: comparisonRate, mtgBalance: mtgBalance!, mthsToMaturity: Double(monthsToMaturity), discount: discount!, currentRate: rate!)

        let threeMthsInterestPenalty = threeMonthsInterestPenalty(mtgBalance: mtgBalance!, mtgRate: rate!)

        print (IRD)
        print (threeMthsInterestPenalty)


        var penalty: Double = 0
       // var totalPenalty: Double = 0

        if IRD > threeMthsInterestPenalty {

            penalty = IRD + cashback
        }else{

            penalty = threeMthsInterestPenalty + cashback
        }



      // totalPenalty = penalty + cashback

         calculationLabel.text = String(penalty)


    }

}
// triggers result based on value selected
   @IBAction func valueChanged(_ sender: UISegmentedControl) {

    switch sender.selectedSegmentIndex {
    case 0:
        calculationLabel.text = String(penalty)

    case 1:
        calculationLabel.text = String(threeMthsInterestPenalty + cashback)

    default:
         calculationLabel.text = String(penalty)
    }


}

编辑:我仍在处理这个问题。我已经更新了上面的代码以显示 IBAction 中的所有代码。 @IBAction 不起作用，因为变量根据它们在代码中的发布位置未定义。 Storyboard有一个 UIsegmentedControl，其值为“固定和可变”。如果用户选择固定，那么我希望它按照 UISegement 控件的 IBAction 显示。

最佳答案

如果您想要检查分段控件的值何时更改，并且您想以编程方式执行此操作，则首先需要使用 valueChanged 常量注册一个目标操作方法。然后，编写您的 valueChanged 函数。检查this了解更多信息。

import UIKit

class ViewController: UIViewController {

    // Reference from Storyboard or Interface Builder
    @IBOutlet weak var mortgageType: UISegmentedControl!

    // For set up a UISegmentedControl programmatically
    var segmentedControl: UISegmentedControl!

    override func viewDidLoad() {
        super.viewDidLoad()
    }

    override func loadView() {
        super.loadView()

        // Programmatically setup
        let items = ["Cinnamon", "Clove"]
        segmentedControl = UISegmentedControl(items: items)
        segmentedControl.selectedSegmentIndex = 0
        segmentedControl.frame = CGRect(x: 120, y: 200, width: 200, height: 30)
        segmentedControl.tintColor = UIColor.black
        segmentedControl.addTarget(self, action: #selector(self.valueChanged(_:)), for: .valueChanged)
        self.view.addSubview(segmentedControl)
    }

    @IBAction func valueChanged(_ sender: UISegmentedControl) {
        switch sender.selectedSegmentIndex {
        case 0:
            print("Hi")

        case 1:
            print("Bye")

        default:
            print("Nothing")
        }
    }
}

如果您从 Storyboard 和 Interface Builder 引用 UISegmentedControl。您还应该向其添加一个 Action 。

已编辑问题的更新

@IBAction func calPenalty(_ sender: UIButton) {
    if mortgageType.selectedSegmentIndex == 0 {
        print("Fixed")
    } else {
        print("Variable")
    }
}

关于ios - UISegmentedControl if 语句，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/44688512/