swift4.2 - UIDynamic

 

1. SB放上俩 imageview，拖线成类属性

?

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126

import UIKit   class ViewController: UIViewController {       @IBOutlet weak var box2: UIImageView!     @IBOutlet weak var box1: UIImageView!           //1.s创建仿真器        private lazy var animator: UIDynamicAnimator = UIDynamicAnimator(referenceView: self.view)     override func viewDidLoad() {         super.viewDidLoad()         //设置背景颜色图         view.backgroundColor = UIColor(patternImage: UIImage.init(named: "background") ?? UIImage())     }           override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {                   let point = touches.first?.location(in: view)         snap(point: point ?? CGPoint.zero)                   gravity()         collision()         push()     }           ///重力     func gravity() {                   //2.创建仿真行为         let behavior = UIGravityBehavior(items: [box1])                   //重力方向，重力的力度 //        behavior.gravityDirection = CGVector(dx: 10, dy: -10)           //        //角度 //        behavior.angle =  -CGFloat.pi // //        //量级：速度 //        behavior.magnitude = 5                   //设置角度和量级         behavior.setAngle( CGFloat.pi/2, magnitude: 5)                   //3. 仿真器添加仿真行为         animator.addBehavior(behavior)     }                 /// 碰撞     func collision() {                   //2.创建仿真行为         let behavior = UICollisionBehavior(items: [box1, box2])                   //添加碰撞边界: view的bounds         behavior.translatesReferenceBoundsIntoBoundary = true   //        items: 只碰撞元素 //        boundaries：只碰撞边界 //        everything:任何东西         //碰撞模式         behavior.collisionMode = UICollisionBehavior.Mode.everything                   //设置边界的内边距 //        behavior.setTranslatesReferenceBoundsIntoBoundary(with: UIEdgeInsets(top: 20, left: 20, bottom: 20, right: 20))                   let str :  NSString = "123" // NSString 遵循NSCopying         let str1 : String = "123"   //String 没有遵循NSCopying         //添加一个边界 //        behavior.addBoundary(withIdentifier: str, from: CGPoint(x: 0, y: 500), to: CGPoint(x: view.frame.size.width, y: 300))                             //设置代理         behavior.collisionDelegate = self         //3. 仿真器添加仿真行为         animator.addBehavior(behavior)     }             /// 创建捕捉行为     func snap(point:CGPoint){         //FIXME:如果想要多次执行p捕捉行为，必须先移除添加捕捉行为         animator.removeAllBehaviors()                   let behavior = UISnapBehavior(item: box2, snapTo: point)                   //动画流畅度         behavior.damping = 1                   animator.addBehavior(behavior)     }       func push(){                   // continuous:一直推         // instantaneous:推一次         //1.创建推行为         let behavior = UIPushBehavior(items: [box1], mode: UIPushBehavior.Mode.instantaneous)                   //设置方向         behavior.pushDirection = CGVector(dx: 0, dy: -8)                   //2. 仿真器添加仿真行为         animator.addBehavior(behavior)     }       }     extension ViewController:UICollisionBehaviorDelegate{     func collisionBehavior(_ behavior: UICollisionBehavior, beganContactFor item1: UIDynamicItem, with item2: UIDynamicItem, at p: CGPoint){         print("开始碰撞 元素 - 元素", p)     }           func collisionBehavior(_ behavior: UICollisionBehavior, endedContactFor item1: UIDynamicItem, with item2: UIDynamicItem){         print("结束碰撞 元素 - 元素")     }           func collisionBehavior(_ behavior: UICollisionBehavior, beganContactFor item: UIDynamicItem, withBoundaryIdentifier identifier: NSCopying?, at p: CGPoint){         print("开始碰撞 元素 - 边界", p)     }           func collisionBehavior(_ behavior: UICollisionBehavior, endedContactFor item: UIDynamicItem, withBoundaryIdentifier identifier: NSCopying?){         print("结束碰撞 元素 - 边界")     } }