swift - UIKit 碰撞检测和 Action

Question

我正在使用 swift 开发 iOS 应用程序，但遇到了问题。仅使用 UIKit，我有一个落在平台上的正方形，弹回其原始位置并继续前进。我希望平台在每次正方形撞击时改变颜色，但我不知道如何检测正方形是否已与平台接触。请帮忙。这是代码

import UIKit
import SpriteKit




class PlayScreen : UIViewController {

    @IBOutlet var ScreenBack: UIImageView!
    @IBOutlet var Platform: UIImageView!

    var squareView: UIImageView!
    var gravity: UIGravityBehavior!
    var animator: UIDynamicAnimator!
    var collision: UICollisionBehavior!
    var itemBehaviour: UIDynamicItemBehavior!

    override func viewDidAppear(animated: Bool) {
    super.viewDidAppear(true)

    // Creating a bouncing Ball with the barrier of the platform
    squareView = UIImageView(frame: CGRect(x: ScreenBack.frame.width/2, y: ScreenBack.frame.height/4, width: 40, height: 40))
    squareView.frame.origin.x-=squareView.frame.width/2
    squareView.image = redBall
    view.addSubview(squareView)

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

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


    itemBehaviour = UIDynamicItemBehavior(items: [squareView])
    itemBehaviour.elasticity = 1.0
    itemBehaviour.resistance = 0.0
    animator.addBehavior(itemBehaviour)

    }
}

Answer 1

使用 UICollisionBehaviorDelegate 检测碰撞

class ViewController: UIViewController, UICollisionBehaviorDelegate {

将你的碰撞行为对象委托(delegate)给自己

collision.collisionDelegate=self

添加添加如下函数

func collisionBehavior(behavior: UICollisionBehavior, beganContactForItem item: UIDynamicItem, withBoundaryIdentifier identifier: NSCopying, atPoint p: CGPoint) {
     println("Contact - \(identifier)")
}