Question

我只是想改变CALayer数组最后一个元素的背景颜色。这是我的整个View Class，但是它实际上只有2-3行才能访问CALayer的最后一个元素。

这是我的progressViewClass，我把评论放在我的问题所在：

class ProgressBarView: UIView {

//Variables for progress bar
var holdGesture = UILongPressGestureRecognizer()
let animation = CABasicAnimation(keyPath: "bounds.size.width")
var layerHolder = [CALayer]()
var widthIndex = CGPoint(x: 0, y: 0)
var nextXOffset = CGFloat(0.0)
var checkIfFull = CGFloat()
var newLayer : CALayer?
var progressBarAnimationDuration : CFTimeInterval = (MainController.sharedInstance.totalMiliSeconsToRecord  / 10)

// Only override draw() if you perform custom drawing.
// An empty implementation adversely affects performance during animation.
override func draw(_ rect: CGRect) {

}

func startProgressBar(){

    if(RecordingViewController().currentCameraMode == .recordingMode || RecordingViewController().currentCameraMode == .record1stClipMode) {

        newLayer = CALayer()
        newLayer?.frame = CGRect(x: nextXOffset, y: 0, width: 0, height: self.bounds.height)
        newLayer?.backgroundColor = UIColor(red:0.82, green:0.01, blue:0.11, alpha:1.0).cgColor

        //print("before \(nextXOffset)")
        newLayer?.anchorPoint = widthIndex
        animation.fromValue = 0
        animation.toValue = self.bounds.width  - nextXOffset
        animation.duration = progressBarAnimationDuration - ((MainController.sharedInstance.miliSecondsPassed) / 10)
        self.layer.addSublayer(newLayer!)

        //print("Long Press Began")
        newLayer?.add(animation, forKey: "bounds.size.width")

    }
    else{
        stopProgressBar()
    }
}

func stopProgressBar(){
    if(RecordingViewController().currentCameraMode != .recordingMode){

            pauseLayer(layer: newLayer!)

            newLayer?.frame = (newLayer?.presentation()!.frame)!
            nextXOffset = (newLayer?.frame.maxX)!
            layerHolder.append(newLayer!)
            print("Layerholder has elements : \(layerHolder.count)")
    }
}

// HERE IS MY PROBLEM
func highlightLastLayer(){
    print("in highlight last layer Layerholder has elements : \(layerHolder.count)")

    // I CAN HIDE THE CALAYER SO I BELIEVE IM ACCESSING THE CORRECT LAYER
    // layerHolder.last?.isHidden = true

    // This is suppose to change the last element background color to blue but doesnt
    layerHolder.last?.backgroundColor = UIColor.blue.cgColor
}

// ALSO MY PROBLEM
func unhighlightLastLayer(){
    print("inside unhighlight last layer")

    // I CAN HIDE THE CALAYER SO I BELIEVE IM ACCESSING THE CORRECT LAYER
    //layerHolder.last?.isHidden = false

    // Changes CALayer back to red
    layerHolder.last?.backgroundColor = UIColor(red:0.82, green:0.01, blue:0.11, alpha:1.0).cgColor
}

//Function to pause the Progress Bar
func pauseLayer(layer : CALayer){
    let pausedTime : CFTimeInterval = layer.convertTime(CACurrentMediaTime(), from: nil)
    layer.speed = 0.0
    layer.timeOffset = pausedTime

}



}

简单地说，我在viewController中创建了一个progressView对象，然后根据某些按钮输入调用这些函数。此视图本质上是一个进度条，您可以在许多视频录制应用程序中看到，以显示您录制了多少。在highlightLastLayer中，我试图抓住＆＃34; layerHolder＆＃34;的最后一个元素。数组并将其颜色更改为蓝色。简单吧？不行。有什么想法吗？

Answer 1

你在哪里叫高亮和不高亮。我很确定你在“停止”或“暂停”时这样做，因为那是你唯一一次向layerHolder数组添加任何内容。您不能在不动画时执行此操作，因为在您动画时，将显示表示层而不是“真实”图层。不要将速度设置为零，而是将图层设置为当前动画状态和调用图层。 removeAllAnimations用于终止表示层并显示视图的实际图层。现在，您可以进行所需的所有更改，它们实际上会显示出来。

Swift：无法更改数组中的CALayer背景颜色

1 个答案: