swift 3 中的 UIDynamicAnimator 落球循环

Question

我有 UIDynamicAnimator 球从上到下掉落，但有时掉 3 个球，有时掉 5 个……等等

但是我在我的for循环中添加了to = 50必须是drop 50 ball

Where is mistake ?

下面是我的代码。

class ViewController: UIViewController {


    var squareView: UIView!
    var numberlet: UILabel!
    var gravity: UIGravityBehavior!
    var animator: UIDynamicAnimator!
    var collision: UICollisionBehavior!
    var itemBehaviour: UIDynamicItemBehavior!

    override func viewDidLoad() {
        super.viewDidLoad()


        let from = 0
        let to = 50
        let by = 1
        for i in stride(from: from, to: to, by: by) {

            let number = randomInt(min: 12, max:99)
            let color = randomInt(min: 1, max:5)

            let seconds = 3 * i
            delayWithSeconds(Double(seconds)) {
                self.start( color : "\(color)", number: "\(number)")
            }

        }

           }
    func randomInt(min: Int, max:Int) -> Int {
        return min + Int(arc4random_uniform(UInt32(max - min + 1)))
    }


    override func loadView() {
        super.loadView()
        view.backgroundColor = UIColor.white

    }



    func start(color : String, number : String){

        squareView = UIView(frame: CGRect(x: view.frame.size.width/2 - 30, y: 0, width: 70, height: 70))
        squareView.layer.cornerRadius = 0
        squareView.backgroundColor = UIColor(patternImage: UIImage(named: "\(color).png")!)
        view.addSubview(squareView)

        numberlet = UILabel(frame:CGRect(x: squareView.frame.size.width/2 - 18 ,  y: 0 , width: 70, height: 70))
        numberlet.textColor = UIColor.black

        numberlet.font =  UIFont.init(name: "Helvetica-Bold", size: 30)
        numberlet.text = number
        squareView.addSubview(numberlet)


        animator = UIDynamicAnimator(referenceView: view)
        gravity = UIGravityBehavior(items: [squareView])
        animator.addBehavior(gravity)

        collision = UICollisionBehavior(items: [squareView])
        collision.translatesReferenceBoundsIntoBoundary = true
        //        collision.addBoundaryWithIdentifier("barrier", fromPoint: CGPointMake(self.view.frame.origin.x, 350), toPoint: CGPointMake(self.view.frame.origin.x + self.view.frame.width, 350))
        animator.addBehavior(collision)

        itemBehaviour = UIDynamicItemBehavior(items: [squareView])
        itemBehaviour.elasticity = 0.3
        animator.addBehavior(itemBehaviour)

        delayWithSeconds(2.9) {
            self.squareView.removeFromSuperview()
            self.numberlet.removeFromSuperview()
          }

    }


    func delayWithSeconds(_ seconds: Double, completion: @escaping () -> ()) {
        DispatchQueue.main.asyncAfter(deadline: .now() + seconds) {
            completion()
        }
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

}

Answer 1

我实现了你的代码。您的问题的原因似乎在于：

let seconds = 3 * i
delayWithSeconds(Double(seconds))             
self.start( color : "\(color)", number: "\(number)")

在你声明 3 * i 的地方，你正在增加放下下一个的时间，所以你的 seconds 将变成 0-3 秒、0-6 秒、0-9 秒、0-12 秒，等等。所以并不是说你没有放下新的方块，而是每次放下下一个方块所需的时间增加了 3 秒。

如果这是预期的行为，那么我不确定您的问题是什么。您的代码在我的设备上运行。

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