arrays - 按顺序循环遍历方 block

Question

我有一个正方形网格，如下所示，我试图弄清楚如何循环遍历每一行(从下到上或反之亦然)，选择一个随机正方形并模拟按下(按比例缩小然后放大) 。我使用以下代码将每一行创建为 5 个 SKShapeNode 的数组:

一排正方形:

//Row Seven
        for var i = -2; i < 3; i++ {

            firstSquare = SKShapeNode(rectOfSize: CGSize(width: self.view!.frame.size.width * (1/5), height: self.view!.frame.size.width * (1/5)))
            firstSquare.fillColor = SKColor(hue: 225.0/360.0, saturation: 0.1176, brightness: 0.2667, alpha: 1.0)
            firstSquare.strokeColor = SKColor.clearColor()
            firstSquare.position = CGPoint(
                x: CGRectGetMidX(self.frame) + ((firstSquare.frame.size.width + CGFloat(2)) * CGFloat(i)),
                y: (CGRectGetMidY(self.frame) + self.frame.size.height / 4) - (firstSquare.frame.size.width + CGFloat(2)) * CGFloat(6))
            rowSeven.append(firstSquare)
            addChild(firstSquare)

        }

七行中的每一行都添加到保存所有行的数组 (gameLayers) 中。

gameLayers = [rowOne, rowTwo, rowThree, rowFour, rowFive, rowSix, rowSeven]

我有以下代码来循环遍历 gameLayers 数组并选择每一行，选择一个随机元素并运行按下的动画。

private func randomIntergerInRange(low:Int, high: Int) -> Int {
        let randomGeneratedNumber = low + Int(arc4random()) % (high - low);
        return Int(randomGeneratedNumber)
    }

func loopThrough() {

for eachRow in gameLayers {

    let selectedSquare = eachRow[randomIntergerInRange(0, high: eachRow.count)]

    let delay = dispatch_time(DISPATCH_TIME_NOW, Int64(Double(2) * Double(NSEC_PER_SEC)))
        dispatch_after(delay, dispatch_get_main_queue()) {

            let scaleDown = SKAction.scaleTo(0.85, duration: 0.3)
            let scaleUp = SKAction.scaleTo(1.0, duration: 0.3)
            let scalingSequence = SKAction.sequence([scaleDown, scaleUp])

            selectedSquare.runAction(scalingSequence)

    }
}

}

在尝试此操作时，每行都会选择一个方 block ，但所有选定的方 block 都会同时运行动画，而不是像我希望的那样按顺序运行。

任何想法可能是什么原因。我认为 for 循环会按顺序运行每个元素的动画。

Answer 1

我认为这个问题可以通过递归循环来使用。在一行的正方形上运行动画后，调用相同的函数并更新该行以触发动画。

var selectedRowIndex = 0

    func loopThrough() {
            let rowSelected = gameLayers[selectedRowIndex] //Select a row from the gameLayers


            let selectedNumber = self.randomIntergerInRange(0, high: rowSelected.count)
            let squareSelected = rowSelected[selectedNumber] //Select a square from the selected Row. 

            //Run the animation on that square
            let scaleDown = SKAction.scaleTo(0.9, duration: 0.2)
            let scaleUp = SKAction.scaleTo(1.0, duration: 0.2)
            let scalingSequence = SKAction.sequence([scaleDown,
                    scaleUp])

            squareSelected.runAction(scalingSequence)


            let delay = dispatch_time(DISPATCH_TIME_NOW, Int64(Double(1.3) * Double(NSEC_PER_SEC)))
                dispatch_after(delay, dispatch_get_main_queue()) {

//Delay for 1.3 seconds and call the function again. Increase the index of the selected row to select the next 
                    if self.selectedRowIndex != self.gameLayers.count - 1 {
                        self.selectedRowIndex++
                        self. loopThrough()
                    }
            }
     }