swift - 在不同的类中使用 function() 变量 - Swift

Question

如何在 customView 类中使用 getLevel() 的值？该函数与 NSTimer 链接。这些值是 mp3 文件的分贝值，我想在 customView 中使用它来将分贝值与动画同步

class customView: UIView {

// get getLevels() value

}


class ViewController: UIViewController, AVAudioPlayerDelegate {


override func viewDidLoad() {
    super.viewDidLoad()



   var bundle = NSString(string: NSBundle.mainBundle().pathForResource("guitar", ofType: "mp3")!)
   var error: NSError? = nil
   player = AVAudioPlayer(contentsOfURL: NSURL(string: bundle), error: &error)
   player.delegate = self
   player.volume = 1.0
   player.meteringEnabled = true
   player.play()



    var timer = NSTimer.scheduledTimerWithTimeInterval(0.1, target: self, selector: Selector("getLevel"), userInfo: nil, repeats: true)

}


func getLevel() {

    if (player.playing == true) {

        player.updateMeters()
        var dblevel = player.averagePowerForChannel(1)
        var percentage = CGFloat( pow(10, (0.05 * dblevel)) * 100)

        // This prints out the the decibel levels from 0.0 to 100.0 every 0.1 sec
        println(percentage)


    }

}

我需要的变量是“百分比”。我有什么选择来做到这一点？谢谢戈达特。

Answer 1

代码中的注释应该是您理解这一点所需的全部内容:

class CustomView: UIView {
    var percentage: CGFloat = 0.0 {
        didSet {
            setNeedsDisplay() // this will cause the system to tell the view to draw itself.
        }
    }

    func drawRect(rect: Rect) {
        // draw yourself based on percentage
    }
}

class ViewController: ... {
    func getLevel() {

        if (player.playing == true) {

            player.updateMeters()
            var dblevel = player.averagePowerForChannel(1)
            var percentage = CGFloat( pow(10, (0.05 * dblevel)) * 100)

            myCustomView.percentage = percentage // this is how to pass the information.
        }
    }
}