UIPanGesture 与 NSTimer 问题

Question

我遇到了一个问题 我有一个视图控制器，它包含一个平移手势和一个 NSTimer，它有一个每秒调用一次的选择器 问题是每次激活计时器时，我尝试使用平移手势移动的标签会自动返回其原始位置。 可能是什么原因？

这里是代码

import UIKit

class gameViewController: UIViewController {


    @IBOutlet weak var img1: UIImageView!
    @IBOutlet weak var lbl1: UILabel!


    @IBOutlet weak var timerLabel: UILabel!
    @IBOutlet weak var gameDifficultyLabel: UILabel!

    var timer = NSTimer()
    var timeManager = TimerManager()

    override func viewDidLoad() {
        super.viewDidLoad()
        timerLabel.text = "\(timeManager.displayedTime(timeManager.time!))"
        // Do any additional setup after loading the view.
        timer = NSTimer.scheduledTimerWithTimeInterval(1, target: self, selector: "updateTime", userInfo: nil, repeats: true)
    }
    override func viewWillAppear(animated: Bool) {
        super.viewWillAppear(animated)
        if let difficulty = timeManager.difficulties {
            switch difficulty {
            case .Easy:
                gameDifficultyLabel.text = "Easy"
            case .Medium:
                gameDifficultyLabel.text = "Medium"
            case .Hard:
                gameDifficultyLabel.text = "Hard"
            }
        }
    }

    @IBAction func panGesture(sender: UIPanGestureRecognizer) {
        let translation = sender.translationInView(self.view)
        if let view = sender.view {
            view.center = CGPoint(x:view.center.x + translation.x,
                y:view.center.y + translation.y)
        }
        sender.setTranslation(CGPointZero, inView: self.view)
    }


    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }
    func updateTime() {
        let shouldStop = timeManager.updateTime()
        timerLabel.text = timeManager.displayedTime(timeManager.time)
        if shouldStop {
            timer.invalidate()
        }
    }
}

更新： 我已经更新了代码。 添加标签以编程方式解决了这个问题，但我遇到了另一个问题 这是代码。

class gameViewController: UIViewController {

@IBOutlet var numbersContainers: [UIImageView]!
@IBOutlet var numbersLabel: [UILabel]!

@IBOutlet weak var timerLabel: UILabel!
@IBOutlet weak var gameDifficultyLabel: UILabel!

var LabelsBackground = [UIImageView]()
var Labels = [UILabel]()

var timer = NSTimer()
var timeManager = TimerManager()

var panGesture : UIPanGestureRecognizer!
override func viewDidLoad() {
    super.viewDidLoad()
    timerLabel.text = "\(timeManager.displayedTime(timeManager.time!))"
    self.createLabelsBackground()
    self.setUpLabelsBackground()
    self.addLabelsBackground()

    self.createLabels()
    self.setUpLabels()
    self.addLabels()

    panGesture = UIPanGestureRecognizer(target: self, action: "panAction:")
    panGesture.minimumNumberOfTouches = 1
    panGesture.maximumNumberOfTouches = 1

}
override func viewDidAppear(animated: Bool) {
    super.viewDidAppear(animated)
    timer = NSTimer.scheduledTimerWithTimeInterval(1, target: self, selector: "updateTime", userInfo: nil, repeats: true)
    self.addPanGesture()
}
override func viewWillAppear(animated: Bool) {
    super.viewWillAppear(animated)
    if let difficulty = timeManager.difficulties {
        switch difficulty {
        case .Easy:
            gameDifficultyLabel.text = "Easy"
        case .Medium:
            gameDifficultyLabel.text = "Medium"
        case .Hard:
            gameDifficultyLabel.text = "Hard"
        }
    }
}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
}
func updateTime() {
    let shouldStop = timeManager.updateTime()
    timerLabel.text = timeManager.displayedTime(timeManager.time)
    if shouldStop {
        timer.invalidate()
    }
}
func createLabelsBackground() {
    for _ in 0..<10 {
        if let img = UIImage(named: "noContainer") {
            LabelsBackground.append(UIImageView(image: img))
        }

    }
}
func setUpLabelsBackground() {
    for i in 0..<10 {
        LabelsBackground[i].frame = numbersContainers[i].frame
        LabelsBackground[i].center = numbersContainers[i].center
    }
}
func addLabelsBackground() {
    for background in LabelsBackground {
        self.view.addSubview(background)
    }
}

func createLabels() {
    for _ in 0..<10 {
        Labels.append(UILabel())
    }
}
func setUpLabels() {
    for i in 0..<10 {
        Labels[i].frame = numbersLabel[i].frame
        Labels[i].center = numbersLabel[i].center
        Labels[i].backgroundColor = UIColor.whiteColor()
        Labels[i].userInteractionEnabled = true
    }
}
func addLabels() {
    for label in Labels {
        self.view.addSubview(label)
    }
}

func addPanGesture(){
    for label in Labels {
        label.text = "10"
        label.addGestureRecognizer(panGesture)
    }
}

func panAction(recognizer: UIPanGestureRecognizer) {
    print("panAction")
    let translation = recognizer.translationInView(self.view)
    if let myView = recognizer.view {
        myView.center = CGPoint(x: myView.center.x + translation.x, y: myView.center.y + translation.y)
    }
    recognizer.setTranslation(CGPointZero, inView: self.view)
}

}

只是为了澄清 @IBOutlet var numbersLabel：[UILabel]！ var 标签 = UILabel

numbersLabels 是使用情节提要添加的空标签，仅用于在以编程方式创建标签时进行定位。

问题在于以编程方式创建并添加到标签数组的标签没有响应。

Answer 1

我认为您确实启用了自动布局（默认情况下已启用）。如果您没有为视图指定任何约束（例如您的标签），Storyboard 将在构建时为您创建它们。您可以通过查看标签的 Size Inspector 设置来验证这一点。

当updateTime() 被调用时，自动布局会根据情节提要为其自动创建的约束将您的标签放回其原始位置。

要解决此问题，您可以：

1) 以编程方式创建标签，而不是在情节提要中创建标签。

或

2) 在情节提要中为您的标签位置添加显式约束，然后为这些约束创建@IBOutlets，并通过更改这些约束的constant 属性而不是更改其框架（中心）在代码中移动标签。