Set<UITouch> 在 iOS Swift 游戏中不起作用

Question

我正在使用 Xcode v7.0 中的 Swift 2.0 制作类似于 Fruit Ninja 的游戏。但是，在 touchesBegan、touchesMoved 和 touchesCancelled 覆盖函数中，我收到以下三个错误：

“'Set' 类型的值没有成员 'anyObject'”出现两次并且 “可选类型 'Set' 的值未展开；您的意思是使用“！”还是“？”？来一次。

这里是代码

override func touchesBegan(touches: Set<UITouch>, withEvent event: UIEvent?) {
    let touch = touches.anyObject() as UITouch
    let location = touch.locationInNode(self)

    activeSlicePoints.append(location)
    redrawActiveSlice()

    activeSliceBG.removeAllActions()
    activeSliceFG.removeAllActions()

    activeSliceBG.alpha = 1
    activeSliceFG.alpha = 1

}

override func touchesMoved(touches: Set<UITouch>, withEvent event: UIEvent?) {
    let touch = touches.anyObject() as UITouch
    let location = touch.locationInNode(self)

    activeSlicePoints.append(location)
    redrawActiveSlice()

}

override func touchesEnded(touches: Set<UITouch>, withEvent event: UIEvent?) {
    activeSliceBG.runAction(SKAction.fadeOutWithDuration(0.25))
    activeSliceFG.runAction(SKAction.fadeOutWithDuration(0.25))

}

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

Here is an image of on what lines the errors appear

感谢所有帮助。提前致谢。

Answer 1

let touch =  touches.first as? UITouch

这将使您获得第一个触摸对象。

像这样使用它：

override func touchesBegan(touches: Set<UITouch>, withEvent event: UIEvent?) {
    if let touch = touches.first {
        // ...
    }
    super.touchesBegan(touches, withEvent:event)
}