ios - 更改 slider 上的动画速度

Question

如果滚动到底部，您会看到一个用于更改动画速度的 slider 。我想做的是基于 replicatorLayer animation2() 部分在 slider 上创建动画速度。这可能吗？

var player:AVAudioPlayer = AVAudioPlayer()
var meditationState: MeditationState?
var replicatorLayer = CAReplicatorLayer()
var dot = CALayer()

func updateTimer(){

    seconds += 1
    timerclock.text = "\(seconds)"
}

// Animation starts running

func animation2() {

    // A layer that creates a specified number of copies of its sublayers (the source layer), each copy potentially having geometric, temporal, and color transformations applied to it.
    replicatorLayer = CAReplicatorLayer()

    // The layer’s bounds rectangle. Animatable.
    replicatorLayer.bounds = CGRect(x: 0.0, y: 0.0, width: 300.0, height: 300.0)

    // The radius to use when drawing rounded corners for the layer’s background. Animatable.
    replicatorLayer.cornerRadius = 10.0

    // The background color of the receiver. Animatable.
    replicatorLayer.backgroundColor = UIColor(white: 0.0, alpha: 0.0).cgColor

    // The layer’s position in its superlayer’s coordinate space. Animatable.
    replicatorLayer.position = view.center

    // calling this method creates an array for that property and adds the specified layer to it.
    view.layer.addSublayer(replicatorLayer)


    // connectng the animation to the content

    // An object that manages image-based content and allows you to perform animations on that content
     dot = CALayer()

    // The layer’s bounds rectangle. Animatable.
    dot.bounds = CGRect(x: 0.0, y: 0.0, width: 12.0, height: 12.0)

    //The layer’s position in its superlayer’s coordinate space. Animatable.
    dot.position = CGPoint(x: 150.0, y: 40.0)

    //The background color of the receiver. Animatable.
    dot.backgroundColor = UIColor(white: 0.2, alpha: 1.0).cgColor

    // The color of the layer’s border. Animatable.
    dot.borderColor = UIColor(white: 1.0, alpha: 1.0).cgColor

    // The width of the layer’s border. Animatable.
    dot.borderWidth = 1.0

    //The radius to use when drawing rounded corners for the layer’s background. Animatable.
    dot.cornerRadius = 5.0


    //Appends the layer to the layer’s list of sublayers.
    replicatorLayer.addSublayer(dot)

    // number of copies of layer is instanceCount

    let nrDots: Int = 1000

    //The number of copies to create, including the source layers.
    replicatorLayer.instanceCount = nrDots

    // The basic type for floating-point scalar values in Core Graphics and related frameworks.
    let angle = CGFloat(2*M_PI) / CGFloat(nrDots)

    // The transform matrix applied to the previous instance to produce the current instance. Animatable.
    replicatorLayer.instanceTransform = CATransform3DMakeRotation(angle, 0.0, 0.0, 1.0)

    // Type used to represent elapsed time in seconds.
    let duration: CFTimeInterval = 10.0

    // animation capabilities for a layer property.

    // An object that provides basic, single-keyframe animation capabilities for a layer property.
    let shrink = CABasicAnimation(keyPath: "transform.scale")

    // Defines the value the receiver uses to start interpolation.
    shrink.fromValue = 1.0

    // Defines the value the receiver uses to end interpolation.
    shrink.toValue = 0.1

    // Specifies the basic duration of the animation, in seconds.
    shrink.duration = duration

    // Determines the number of times the animation will repeat.
    shrink.repeatCount = Float.infinity

    // Add the specified animation object to the layer’s render tree.
    dot.add(shrink, forKey: "shrink")

    // Specifies the delay, in seconds, between replicated copies. Animatable.
    replicatorLayer.instanceDelay = duration/Double(nrDots)

    // The transform applied to the layer’s contents. Animatable.
    dot.transform = CATransform3DMakeScale(0.01, 0.01, 0.01)
}

// connecting the breathe in label

@IBOutlet weak var label: UILabel!

// instant delay

@IBOutlet weak var instantDelay: UIButton!
@IBAction func delayBtn(_ sender: Any) {

    dot.removeAnimation(forKey: "shrink")
    timer1.invalidate()
    seconds = 0
    timer2.invalidate()
    timerclock.text = "\(seconds)"
    time = 0
    timerLabel.text = "Breathe in"
    timerisOn = false
    pauseBtn.isHidden = true
    playBtn.isHidden = false

    label.isHidden = true
    replicatorLayer.isHidden = true
    instantDelay.isHidden = true
    instantDelay1.isHidden = false
    slider.isHidden = false
}

// Delay 1

@IBOutlet weak var instantDelay1: UIButton!
@IBAction func delayBtn1(_ sender: Any) {


    instantDelay1.isHidden = true
    instantDelay.isHidden = false
    label.isHidden = false
    slider.isHidden = true
}


//Slider for changing animation speed

@IBOutlet weak var slider: UISlider!
@IBAction func slider(_ sender: Any) {

}

Answer 1

CALayer 符合CAMediaTiming 协议(protocol)，这意味着它有一个speed 属性。当您更改图层的 speed 属性时，它会更改所有子图层的“参照系”。 (speed == 1.0为正常速度，speed 2.0为倍速，speed 0.5为半速。)

您可以更改包含复制器层的父层的 speed 属性，它会改变动画的速度。尝试制作一个附加到 slider 的 valueChanged IBAction，将动画 super 层的速度属性更改为 0.5 到 2.0 之间的值。

CAAnimation 对象也符合 CAMediaTiming 协议(protocol)，因此您也可以更改单个动画的速度。

编辑:

并不复杂。你可以使你的 slider IBAction 方法像这样:

@IBAction func slider(_ sender: UISlider) {
  view.layer.speed = sender.value
}