ios - 在分段控制中使用未解析的标识符

Question

我的应用程序中有一个场景，我想在两个 slider 和用户选择的分段控件之间进行基本数学运算。我正在尝试在分段控件下的变量之间进行数学运算，但 Xcode 给了我一个 (!) 声明

Use of unresolved identifier "xxxx"

无论我想添加什么变量。我的代码是:

import UIKit

class DopamineCalculator: UIViewController {

//slider outlets
@IBOutlet weak var slider: UISlider!
@IBOutlet weak var sliderone: UISlider!
//segmentoutlet
@IBOutlet weak var segmentoutlet: UISegmentedControl!


//LABELS
//weight label
@IBOutlet weak var weightlabel: UILabel!
//dosage label
@IBOutlet weak var dosagemg: UILabel!
 //Drip Rate Answer Label
@IBOutlet weak var dripanswer: UILabel!




//ACTIONS!!
//weight slider action
@IBAction func weightslider(sender: UISlider) {

    let weight = Int(sender.value)
    //converts to kgs
    let kgs = Int(sender.value) / Int(2.2)

    weightlabel.text = "\(weight) lbs"
}


//Dosage Desired dosage slider

@IBAction func dosagedesired(sender: UISlider) {

    let dosage = Int(sender.value)



    dosagemg.text = "\(dosage) mg"
}


//CONCENTRATION OPTIONS
@IBAction func concentrationoption(sender: UISegmentedControl) {
        switch segmentoutlet.selectedSegmentIndex
        {
        case 0:


            dripanswer.text = (kgs) * (dosage) / 800


        case 1:


            dripanswer.text = "1600";



        case 2:


            dripanswer.text = "3200";

        default:
            break;
    }
}

我想做的是每种情况下分别计算 kgs x dosage/800。对于 Unresolved 标识符问题，我在网上找不到合适的解决方案。

Answer 1

@IBOutlet ...

// Add variables to be reachable for all methods    
var dosage : Int = 0
var kgs : Double = 0.0
var divisor : Double = 800.0 

@IBAction func dosagedesired(sender: UISlider) {

    // prepend self to variable as it is used
    self.dosage = Int(sender.value)
    dosagemg.text = "\(self.dosage) mg"
    // adding the calculation here
    let result = self.kgs * Double(self.dosage) / self.divisor
    dripanswer.text = "\(result)"
}

@IBAction func weightslider(sender: UISlider) {
    let weight = Int(sender.value)    
    // converts to kgs
    // the same here
    self.kgs = Int(sender.value) / Int(2.2)
    // adding the calculation here
    let result = self.kgs * Double(self.dosage) / self.divisor
    dripanswer.text = "\(result)"
}

@IBAction func concentrationoption(sender: UISegmentedControl) {

    switch segmentoutlet.selectedSegmentIndex
    {
        case 0:                
            self.divisor = 800.0            
        case 1:
            self.divisor = 1600.0
        case 2:
            self.divisor = 3200.0
        default: 
            self.divisor = 800.0
    }
    // finally the calculation 
    let result = self.kgs * Double(self.dosage) / self.divisor
    dripanswer.text = "\(result)"            
}