IOS真机有warning, Sending `recording` with no listeners registered. about react-native-recording

[jiyarong]

 Sound.setCategory('Record')

#在录音之前把Sound的类型设置为这个，问题就全解决了

[jiyarong]

我拉了你的example，发现没问题，于是我就怀疑是跟我某个包有冲突了，经过排查发现是react-native-sound，只要装了这个包，IOS真机(其他的都没问题，只有真机)就会出现Sending recording with no listeners registered.

这个是sound的项目地址https://github.com/zmxv/react-native-sound

这是他的index.js

// Type definitions for react-native-sound
// Project: https://github.com/zmxv/react-native-sound
// Definitions by: Kyle Roach <https://github.com/iRoachie>
// TypeScript Version: 2.3.2

type AVAudioSessionCategory = 'Ambient' | 'SoloAmbient' | 'Playback' | 'Record' | 'PlayAndRecord' | 'AudioProcessing' | 'MultiRoute'

type AVAudioSessionMode = 'Default' | 'VoiceChat' | 'VideoChat' | 'GameChat' | 'VideoRecording' | 'Measurement' | 'MoviePlayback' | 'SpokenAudio'

export default class Sound {
  static MAIN_BUNDLE: string
  static DOCUMENT: string
  static LIBRARY: string
  static CACHES: string

  /**
   * Sets AVAudioSession as active, which is recommended on iOS to achieve seamless background playback.
   * Use this method to deactivate the AVAudioSession when playback is finished in order for other apps
   * to regain access to the audio stack.
   * 
   * @param category AVAudioSession category
   * @param mixWithOthers Can be set to true to force mixing with other audio sessions.
   */
  static setActive(active: boolean): void

  /**
   * Sets AVAudioSession category, which allows playing sound in background, 
   * stop sound playback when phone is locked, etc. 
   * Parameter options: "Ambient", "SoloAmbient", "Playback", "Record", "PlayAndRecord", "AudioProcessing", "MultiRoute".
   * 
   * @param category AVAudioSession category
   * @param mixWithOthers Can be set to true to force mixing with other audio sessions.
   */
  static setCategory(category: AVAudioSessionCategory, mixWithOthers: boolean): void

  /**
   * Sets AVAudioSession mode, which works in conjunction with the category to determine audio mixing behavior.
   * Parameter options: "Default", "VoiceChat", "VideoChat", "GameChat", "VideoRecording", "Measurement", "MoviePlayback", "SpokenAudio".
   * 
   * @param mode AVAudioSession mode
   * @param mixWithOthers Can be set to true to force mixing with other audio sessions.
   */
  static setMode(mode: AVAudioSessionMode): void

  /**
   * @param filename Either absolute or relative path to the sound file
   * @param basePath Optional base path of the file. Omit this or pass '' if filename is an absolute path. Otherwise, you may use one of the predefined directories: Sound.MAIN_BUNDLE, Sound.DOCUMENT, Sound.LIBRARY, Sound.CACHES.
   * @param onError Optional callback function if loading file failed
   */
  constructor(filename: string, basePath: string, onError: (error: any) => void)

  /**
   * Return true if the sound has been loaded.
   */
  isLoaded(): boolean

  /**
   * Plays the loaded file
   * @param onEnd - Optional callback function that gets called when the playback finishes successfully or an audio decoding error interrupts it
   */
  play(onEnd?: () => void): void

  /**
   * Pause the sound
   * @param cb - Optional callback function that gets called when the sound has been paused.
   */
  pause(cb?: () => void): void

  /**
   * Stop playback and set the seek position to 0.
   * @param cb - Optional callback function that gets called when the sound has been stopped.
   */
  stop(cb?: () => void): void

  /**
   * Release the audio player resource associated with the instance.
   */
  release(): void

  /**
   * Return the number of channels 
   * (1 for mono and 2 for stereo sound), or -1 before the sound gets loaded.
   */
  getNumberOfChannels(): number

  /**
   * Return the volume of the audio player (not the system-wide volume),
   * Ranges from 0.0 (silence) through 1.0 (full volume, the default)
   */
  getVolume(): number

  /**
   * Set the volume
   * @param value - ranging from 0.0 (silence) through 1.0 (full volume)
   */
  setVolume(value: number): void

  /**
   * Return the stereo pan position of the audio player (not the system-wide pan)
   * Ranges from -1.0 (full left) through 1.0 (full right). The default value is 0.0 (center)
   */
  getPan(): number

  /**
   * Set the pan value
   * @param value - ranging from -1.0 (full left) through 1.0 (full right).
   */
  setPan(value: number): void

  /**
   * Return the loop count of the audio player. 
   * The default is 0 which means to play the sound once. 
   * A positive number specifies the number of times to return to the start and play again. 
   * A negative number indicates an indefinite loop.
   */
  getNumberOfLoops(): number

  /**
   * Set the loop count
   * @param value - 0 means to play the sound once. A positive number specifies the number of times to return to the start and play again (iOS only). A negative number indicates an indefinite loop (iOS and Android).
   */
  setNumberOfLoops(value: number): void

  /**
   * Callback will receive the current playback position in seconds and whether the sound is being played.
   * @param cb 
   */
  getCurrentTime(cb?: (seconds: number, isPlaying: boolean) => void): void

  /**
   * Seek to a particular playback point in seconds.
   * @param value 
   */
  setCurrentTime(value: number): void

  /**
   * Speed of the audio playback (iOS Only).
   * @param value 
   */
  setSpeed(value: number): void

  /**
   * Whether to enable playback in silence mode (iOS only)
   * @deprecated - Use the static method Sound.setCategory('Playback') instead which has the same effect.
   * @param enabled 
   */
  enableInSilenceMode(enabled: boolean): void

  /**
   * Sets AVAudioSession category
   * @deprecated
   * @param value 
   */
  setCategory(value: AVAudioSessionCategory): void

  /**
   * Turn speaker phone on (android only)
   * @param value
   */
  setSpeakerphoneOn(value: boolean): void
}

oc的代码我不太懂，有没有可能是命名冲突，假如不用sound我这边也要改不少代码，边录边获取流的包全github大概就你这个能用了，我们这边是小团队，没什么大牛，非常能希望结交想你这样的优秀程序员，看到的话不知道能不能给个微信

[qiuxiang]

Sending `recording` with no listeners registered. 的意思是没有注册相应的监听函数，大概是你的写法有问题，与其他库没什么关系，况且，react-native-sound 并没有任何关于 recording 的使用。

退一步，这也只是一个 warning，release 的时候会被忽略的，不过我确实应该在 send event 之前检查
listener 有没有注册。

[jiyarong]

@qiuxiang 同样的代码在安卓的真机和模拟器，还有IOS的模拟器上都是好的，唯有IOS的真机在link了react-native-sound之后会出现获取不到监听数据的情况，至于写法，你的这个组件用起来总共就三行，应该不会出问题的吧

[jiyarong]

我锁定问题了，是sound的这个方法导致的

Sound.setCategory('Playback');

把这个去掉一切正常，一旦启动这个，你的这个包在IOS真机上就没法用了，不过你的这个init方法一旦启用，他的setCategory就不需要设置也能播放声音了，所以我暂时的解决方案是，在初始化App的时候直接Recording.init来代替Sound的setCategory，不过还是希望你的下个版本能解决这个问题

[wangping0105]

应该是 你recording 里面的 setCategory('Playback') 之前先判断下是否已经监听

[oliviachang29]

I wasn't using react-native-sound but was using a different module (react-native-tone). Adding this code to the module fixed the issue:

[audioSession setCategory:AVAudioSessionCategoryPlayAndRecord withOptions:AVAudioSessionCategoryOptionDefaultToSpeaker error:&setCategoryError];