Swift 如何在mehod中更新值？

我是Swift新手，我想用此行更新值：

circleShape.strokeEnd = CGFloat(sum)

每次单击“计算”（以获取总和的值）。我该怎么做

这是我的代码：

@IBOutlet weak var centerCircle: UIImageView!

var num1 = 0.0
var num2 = 0.0
var sum = 0.0
var a = 0.0
var b = 0.0

@IBOutlet weak var label1: UILabel!
@IBOutlet weak var label2: UILabel!
@IBOutlet weak var sumNum: UILabel!


@IBAction func vote1(sender: UIButton) {
    num1 = Double(label1.text!)!
    self.label1.text = String(num1 + 1)
    a = num1 + 1
}

@IBAction func vote2(sender: UIButton) {
    num2 = Double(label2.text!)!
    self.label2.text = String(num2 + 1)
    b = num2 + 1
}

@IBAction func calculate(sender: AnyObject) {


    sum = Double(a/(b+a))
    sumNum.numberOfLines = 0
    sumNum.lineBreakMode = NSLineBreakMode.ByWordWrapping
    sumNum.text = "\(sum)"

}

override func viewDidLoad() {
    super.viewDidLoad()

    // round view
    let roundView = UIView(frame: CGRectMake(85, 100, 150, 150))
    roundView.backgroundColor = UIColor.whiteColor()
    roundView.layer.cornerRadius = roundView.frame.size.width / 2

    // bezier path
    let circlePath = UIBezierPath(arcCenter: CGPoint (x: roundView.frame.size.width / 2, y: roundView.frame.size.height / 2),
                                  radius: roundView.frame.size.width / 2.2 ,
                                  startAngle: CGFloat(-0.5 * M_PI),
                                  endAngle: CGFloat(1.5 * M_PI),
                                  clockwise: true)
    // circle shape
    let circleShape = CAShapeLayer()
    circleShape.path = circlePath.CGPath
    circleShape.strokeColor = UIColor.blackColor().CGColor
    circleShape.fillColor = UIColor.clearColor().CGColor
    circleShape.lineWidth = 14
    // set start and end values
    circleShape.strokeStart = 0.0
    circleShape.strokeEnd = CGFloat(sum)

    // add sublayer
    roundView.layer.addSublayer(circleShape)
    // add subview
    self.view.addSubview(roundView)
    self.view.insertSubview(roundView, belowSubview: centerCircle)

}

---

您需要将

circleShape

声明为全局变量，并在

calculate

函数中修改其

strokeEnd

值

@IBOutlet weak var centerCircle: UIImageView!

var num1 = 0.0
var num2 = 0.0
var sum = 0.0
var a = 0.0
var b = 0.0
let circleShape = CAShapeLayer()

@IBOutlet weak var label1: UILabel!
@IBOutlet weak var label2: UILabel!
@IBOutlet weak var sumNum: UILabel!


@IBAction func vote1(sender: UIButton) {
    num1 = Double(label1.text!)!
    self.label1.text = String(num1 + 1)
    a = num1 + 1
}

@IBAction func vote2(sender: UIButton) {
    num2 = Double(label2.text!)!
    self.label2.text = String(num2 + 1)
    b = num2 + 1
}

@IBAction func calculate(sender: AnyObject) {
    sum = Double(a/(b+a))
    sumNum.numberOfLines = 0
    sumNum.lineBreakMode = NSLineBreakMode.ByWordWrapping
    sumNum.text = "\(sum)"
    circleShape.strokeEnd = CGFloat(sum)
}

override func viewDidLoad() {
    super.viewDidLoad()

    // round view
    let roundView = UIView(frame: CGRectMake(85, 100, 150, 150))
    roundView.backgroundColor = UIColor.whiteColor()
    roundView.layer.cornerRadius = roundView.frame.size.width / 2

    // bezier path
    let circlePath = UIBezierPath(arcCenter: CGPoint (x: roundView.frame.size.width / 2, y: roundView.frame.size.height / 2),
                                  radius: roundView.frame.size.width / 2.2 ,
                                  startAngle: CGFloat(-0.5 * M_PI),
                                  endAngle: CGFloat(1.5 * M_PI),
                                  clockwise: true)
    // circle shape
    circleShape.path = circlePath.CGPath
    circleShape.strokeColor = UIColor.blackColor().CGColor
    circleShape.fillColor = UIColor.clearColor().CGColor
    circleShape.lineWidth = 14
    // set start and end values
    circleShape.strokeStart = 0.0
    circleShape.strokeEnd = CGFloat(sum)

    // add sublayer
    roundView.layer.addSublayer(circleShape)
    // add subview
    self.view.addSubview(roundView)
    self.view.insertSubview(roundView, belowSubview: centerCircle)
}

---

有人能帮忙吗？…非常感谢！真的谢谢！但似乎仍然没有工作。。。假设在更改strokeEnd（或总和）的值后，圆边的颜色会发生变化，但不会发生。你能帮个忙吗？哦！！我发现我只是做错了什么。它起作用了！谢谢你，伙计。