如何使多個對象旋轉？

Question

我正在構建一個應用程序，我需要爲三個按鈕創建重力和旋轉。我爲我的一個按鈕編寫了一個無限旋轉函數，但我不知道如何將它鏈接到其他兩個按鈕。

import UIKit 

class ViewController: UIViewController { 
    var animator: UIDynamicAnimator? 
    var gravity: UIGravityBehavior? 
    var isRotating = false 

    @IBOutlet var Ball1: UIButton! 
    @IBOutlet var Ball2: UIButton! 
    @IBOutlet var Ball3: UIButton! 

    override func viewDidLoad() { 
     super.viewDidLoad() 

     self.animator = UIDynamicAnimator(referenceView: self.view) 

     if !isRotating { 
      // create a spin animation 
      let spinAnimation = CABasicAnimation() 
      // starts from 0 
      spinAnimation.fromValue = 0 
      // goes to 360 (2 * π) 
      spinAnimation.toValue = M_PI*2 
      // define how long it will take to complete a 360 
      spinAnimation.duration = 1 
      // make it spin infinitely 
      spinAnimation.repeatCount = Float.infinity 
      // do not remove when completed 
      spinAnimation.removedOnCompletion = false 
      // specify the fill mode 
      spinAnimation.fillMode = kCAFillModeForwards 
      // and the animation acceleration 
      spinAnimation.timingFunction = CAMediaTimingFunction(name: kCAMediaTimingFunctionLinear) 
      // add the animation to the button layer 
      Ball1.layer.addAnimation(spinAnimation, forKey: "transform.rotation.z") 

     } else { 
      // remove the animation 
      Ball1.layer.removeAllAnimations() 
     } 
     // toggle its state 
     isRotating = !isRotating 
    } 
} 

Answer 1

您可以通過這種方式將動畫層添加到您的UIButtons。

Ball2.layer.addAnimation(spinAnimation, forKey: "transform.rotation.z") 
    Ball3.layer.addAnimation(spinAnimation, forKey: "transform.rotation.z") 

並刪除它們這樣

Ball2.layer.removeAllAnimations() 
Ball3.layer.removeAllAnimations()