ios - 如何让多个物体旋转？

Question

我正在构建一个应用程序，我需要为三个按钮创建重力和旋转。我为我的其中一个按钮编写了一个无限旋转功能，但我不知道如何将它链接到其他两个按钮。

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

您可以通过这种方式将动画层添加到您的 UIButtons。

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

并以这种方式删除它们

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