ios - Swift -- 录音机/变声器应用程序 : How are these functions related?

Question

我正在创建的录音机应用程序中有两个函数(遵循 Udacity 教程。)我试图了解这两个函数是如何相关的:

    @IBAction func recordButton(sender: UIButton) {

    recordB.hidden = true
    inProgress.hidden = false
    stopButtonHide.hidden = false
    let dirPath = NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .UserDomainMask, true)[0] as String

    let currentDateTime = NSDate()
    let formatter = NSDateFormatter()
    formatter.dateFormat = "ddMMyyyy-HHmmss"
    let recordingName = formatter.stringFromDate(currentDateTime)+".wav"
    let pathArray = [dirPath, recordingName]
    let filePath = NSURL.fileURLWithPathComponents(pathArray)
    println(filePath)

    var session = AVAudioSession.sharedInstance()
    session.setCategory(AVAudioSessionCategoryPlayAndRecord, error: nil)


    audioRecorder = AVAudioRecorder(URL: filePath, settings: nil, error: nil)
    audioRecorder.delegate = self
    audioRecorder.meteringEnabled = true
    audioRecorder.prepareToRecord()
    audioRecorder.record()
}

func audioRecorderDidFinishRecording(recorder: AVAudioRecorder!, successfully flag: Bool) {
    if(flag) {
        recordedAudio = RecordedAudio()
        recordedAudio.filePathUrl = recorder.url
        recordedAudio.title = recorder.url.lastPathComponent
        self.performSegueWithIdentifier("stopRecording", sender: recordedAudio)
    } else {
        println("Recording was not succesful")
        recordB.enabled = true
        stopButtonHide.hidden = true
    }

}

第一个函数开始录音(据我所知)，创建并存储一个音频文件(为其命名并获取路径。)第二个函数检查录音是否完成。我的问题是我看不到这两个函数是如何连接的。第二个函数如何知道检查第一个函数中的记录？有一个名为 RecordedAudio.swift 的单独类，它有两个变量:

import Foundation

class RecordedAudio: NSObject{
var filePathUrl: NSURL!
var title: String!
}

为什么我需要这门课？这个类的目的是什么(我知道它是 MVC 的模型部分，但仅此而已)？我试图了解我的代码中发生了什么，因为我在遵循的教程中并不清楚。

Answer 1

1. 似乎 recordedAudio 是一个 RecordedAudio 对象，因此需要该类。

2. audioRecorderDidFinishRecording 是 ( as stated in the docs ) 一个 AVAudioRecorderDelegate 方法，并且会自动...

called by the system when a recording is stopped or has finished due to reaching its time limit.

在这种情况下，“录音”将指的是您在 recordButton: 中创建的 AVAudioRecorder audioRecorder(并且您为其创建已设置其 AVAudioRecorderDelegate 以触发 audioRecorderDidFinishRecording: 方法)。