Swift 返回不适用于UiLabel的值的if语句

我对swift和编程相当陌生，我试图显示if语句中的值。这是我的UiLabel内的func。我尝试了一些类似的变化，但它只返回“calculate.fuelTank”，它似乎从未触发IF语句的第二部分

@IBOutlet weak var startingFuelDisplay: UILabel!  //not working yet
    func refreshUiopeningFuel() {

        if calculate.totalFuel <= Double(calculate.fuelTank) {

            print (Double(calculate.fuelTank)) // FuelTank

        } else {

            print (calculate.totalFuel) // TotalFuel
        }

@IBOutlet弱var启动FuelDisplay:UILabel//还没开始工作
func refreshUiopeningFuel（）{
如果计算总燃料管柱{
返回totalFuelDisplay.text！
}
@IBOUTLE弱var总停止显示：UILabel！
func refreshUiStops（）->字符串{
返回totalStopsDisplay.text！
}
@IBOutlet弱var tyreLifeDisplay:UILabel！
func refreshUiTyreLife（）->字符串{
返回tyrelifesplay.text！
}
@IBOutlet弱var tyreLifeLapsDisplay:UILabel！
func refreshUiTyreLifeLaps（）->字符串{
返回tyreLifeLapsDisplay.text！
}
@IBOUTLE弱var pitOnLapDisplay:UILabel！
func refreshUiBoxOnLap（）{
}
@IBOutlet弱var启动FuelDisplay:UILabel！//尚未工作
func refreshUiopeningFuel（）->Double{
打印（计算燃油箱）
打印（计算总燃油）
if calculate.totalFuel从自然现实逻辑判断，似乎您只是简单地颠倒了if/else逻辑。if
totalFuel
似乎小于油箱的容量（if

子句），在这种情况下，您应该返回

totalFuel

，并在

else

子句中返回油箱容量。

如果在比较之前打印正在比较的两个值，您会看到什么？需要更多信息。您是在尝试在Xcode调试区域获得控制台输出，这是

print

所做的，还是您自己做的您希望

ui标签
启动FuelDisplay
更新其显示？是什么原因导致调用
刷新打开Fuel
的？此处未显示任何内容。您的意思是将其作为一个
@iAction
功能？可能与点击按钮关联？此外，“内”也没有函数一个IBOutlet对象。您的函数
refreshUiopeningFuel（）
位于包含类中的
UILabel
旁边，可能是
class ViewController:UIViewController
。还没有任何东西可以将它们联系在一起，所以请从功能的角度来描述它，以便我们可以告诉您该怎么做。我之前在按下按钮操作时的代码中发现了一个小错误，我将燃油箱声明为结果。我现在修改了“startingFuelDisplay（）”，现在在控制台输出中，我看到func之前的值是我在代码中设置的预设值。显示控制台输出（来自那些
print（）
语句）如果您希望触发
else
子句，则会打印该语句。不，返回到绘图板，这不是必须以另一种方式执行的吗
import UIKit

class ViewController: UIViewController {
    let calculate = Inputs ( raceLaps: 13, fuelRate: 3.7, fuelTank: 110, laptime: 85.456, tyreWear: 0.05 )

    @IBOutlet weak var rate: UITextField!
    @IBOutlet weak var laps: UITextField!
    @IBOutlet weak var tank: UITextField!
    @IBOutlet weak var tyreWear: UITextField!
    @IBOutlet weak var laptime: UITextField!

    @IBOutlet var cancelKeyboard: UITapGestureRecognizer!


    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
        //Looks for single or multiple taps.
        let tap: UITapGestureRecognizer = UITapGestureRecognizer(target: self, action: "dismissKeyboard")
        view.addGestureRecognizer(tap)
    }

    //Calls this function when the tap is recognized.
    func dismissKeyboard() {
        //Causes the view (or one of its embedded text fields) to resign the first responder status.
        view.endEditing(true)

            }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
        refreshUiFuel()
        refreshUiStops()
        refreshUiTyreLife()
        refreshUiTyreLifeLaps()
        refreshUiopeningFuel()
        refreshUiBoxOnLap ()


    }



    @IBAction func calculate(sender: UIButton) {
        if let rateVal = Double(rate.text!),
            tankVal = Int(tank.text!),
            lapVal = Int(laps.text!),
            wearVal = Double(tyreWear.text!),
        laptimeVal: Float = 85.456 {
                let fuelModel = Inputs(raceLaps: lapVal, fuelRate: rateVal, fuelTank: tankVal, laptime: laptimeVal, tyreWear: wearVal )
                totalFuelDisplay.text = ("\(Double(fuelModel.totalFuel))")
                totalStopsDisplay.text = ("\(Int(fuelModel.totalStops))")
                tyreLifeDisplay.text = ("\(Int(fuelModel.tyreChangesRaceDistanceTotal))")
                tyreLifeLapsDisplay.text = ("\(Int(fuelModel.tyreLife))")
                startingFuelDisplay.text = ("\(refreshUiopeningFuel())")
        }
        else {
            totalFuelDisplay.text = "missing value"
            totalStopsDisplay.text = "missing value"
            tyreLifeDisplay.text = "missing value"
            tyreLifeLapsDisplay.text = "missing value"
            startingFuelDisplay.text = "missing Value"
        }

                   }

    @IBOutlet weak var totalFuelDisplay: UILabel!
    func refreshUiFuel()->String {
        return totalFuelDisplay.text!
    }

    @IBOutlet weak var totalStopsDisplay: UILabel!
    func refreshUiStops()->String {
        return totalStopsDisplay.text!
    }

    @IBOutlet weak var tyreLifeDisplay: UILabel!
    func refreshUiTyreLife()->String {
        return tyreLifeDisplay.text!
    }
    @IBOutlet weak var tyreLifeLapsDisplay: UILabel!
    func refreshUiTyreLifeLaps()->String {
        return tyreLifeLapsDisplay.text!
    }
    @IBOutlet weak var pitOnLapDisplay: UILabel!
    func refreshUiBoxOnLap () {

    }



    @IBOutlet weak var startingFuelDisplay: UILabel!  //not working yet
        func refreshUiopeningFuel() ->Double {

            print(calculate.fuelTank)
            print(calculate.totalFuel)

            if calculate.totalFuel <= Double(calculate.fuelTank) {

                return Double(calculate.fuelTank) // FuelTank

            } else {

                return calculate.totalFuel // TotalFuel
            }


  }
}