Swift 2: 'Set<UITouch>' 类型的值没有成员 'anyObject'

Question

我检查了我的旧游戏，我想在 Swift 2.0 中更新它。当我试图修复它时，Xcode 发现了一个错误。错误是 Value of type 'Set' has no member 'anyObject' 这行代码：

var touch:UITouch = touches.anyObject() as! UITouch

函数:

override func touchesEnded(touches: Set<UITouch>, withEvent event: UIEvent?) {

    self.runAction(SKAction.playSoundFileNamed("torpedo.mp3", waitForCompletion: false))

    var touch:UITouch = touches.anyObject() as! UITouch //<-- Here is Error
    var location:CGPoint = touch.locationInNode(self)

    var torpedo:SKSpriteNode = SKSpriteNode(imageNamed: "torpedo")
    torpedo.position = player.position

    torpedo.physicsBody = SKPhysicsBody(circleOfRadius: torpedo.size.width/2)
    torpedo.physicsBody!.dynamic = true
    torpedo.physicsBody!.categoryBitMask = photonTorpedoCategory
    torpedo.physicsBody!.contactTestBitMask = alienCategory
    torpedo.physicsBody!.collisionBitMask = 0
    torpedo.physicsBody!.usesPreciseCollisionDetection = true

    var offset:CGPoint = vecSub(location, b: torpedo.position)

    if (offset.y < 0){
        return

    self.addChild(torpedo)

    var direction:CGPoint = vecNormalize(offset)

    var shotLength:CGPoint = vecMult(direction, b: 1000)

    var finalDestination:CGPoint = vecAdd(shotLength, b: torpedo.position)

    let velocity = 568/1
    let moveDuration:Float = Float(self.size.width) / Float(velocity)

    var actionArray:NSMutableArray =  NSMutableArray()
    actionArray.addObject(SKAction.moveTo(finalDestination, duration: NSTimeInterval(moveDuration)))
    actionArray.addObject(SKAction.removeFromParent())

    torpedo.runAction(SKAction.sequence(actionArray))
}

那么这里要解决什么？

Answer 1

给定 UITouch 的 Set 定义如下

touches: Set<UITouch>

您可以使用此代码检索触摸

let touch = touches.first

泛型

无需将检索到的元素强制转换为 UITouch。事实上，现在用 Objective-C 编写的 Apple API 已经更新为泛型。这意味着在这种情况下，您会收到一个 Set of UITouch（而不是 Set of NSObject，它实际上可以包含任何对象）。所以 Set 已经知道 包含的元素是 UITouch.

可选

first 计算属性执行 return 和 Optional。事实上，如果 Set 为空，它会 return nil.

一个很好且安全的元素展开技术是

guard let touch = touches.first else {
    debugPrint("Ops, no touch found...")
    return
}

// here you can use touch

Swift 2: 'Set<UITouch>' 类型的值没有成员 'anyObject'

Swift 2: Value of type 'Set<UITouch>' has no member 'anyObject'

uitouch

sprite-kit

skspritenode

swift

swift2

泛型

可选