UISegmentedControl if语句

Question

我正在尝试学习UISegmentedControl，并想知道如何让它在if语句中工作，以便根据选择返回一个值，并根据另一个选择返回另一个值。UISegment只能返回两个值-“固定”或"Varibale“。下面的代码不起作用，但给出了我想要的想法。这两个变量是预先定义的。

  @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:我还在研究这个问题。我已经更新了上面的代码，以显示IBAction中的所有代码。@IBAction不工作，因为这些变量是根据它们在代码中的发布位置而未定义的。Storyboard有一个to值“固定和变量”的UIsegmentedControl。如果用户选择“固定”，那么我希望它按照IBAction for UISegement控件显示。

Answer 1

如果您想要的是检查分段控件的值何时发生变化，并且希望以编程方式进行更改，那么首先需要使用valueChanged常量注册一个目标操作方法。然后，编写您的valueChanged函数。有关更多信息，请查看这。

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引用您的UISegmentedControl。您还应该向它添加一个操作。

​

更新到已编辑的问题

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