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flutter开发实战-just_audio实现播放音频暂停音频设置音量等

最近开发过程中遇到需要播放背景音等音频播放，这里使用just_audio来实现播放音频暂停音频设置音量等

一、引入just_audio

在pubspec.yaml引入just_audio

  just_audio: ^2.7.0

在iOS上，video_player使用的是AVPlayer进行播放。
在Android上，video_player使用的是ExoPlayer。

二、使用前设置

2.1 在iOS中的设置
在iOS工程中info.plist添加一下设置，以便支持Https，HTTP的视频地址

<key>NSAppTransportSecurity</key>
<dict><key>NSAllowsArbitraryLoads</key><true/>
</dict>

2.2 在Android中的设置
需要在/android/app/src/main/AndroidManifest.xml文件中添加网络权限

<uses-permission android:name="android.permission.INTERNET"/>

三、just_audio实现播放音频暂停音频设置音量等

引入just_audio后，可以使用AudioPlayer来播放音频

3.1 常用操作如下

• 播放

await _audioPlayer.play();

• 暂停

await _audioPlayer.pause();

• seek

await _audioPlayer.seek(position);

• 停止

await _audioPlayer.pause();
await _audioPlayer.seek(Duration.zero);

• 设置音量

await _audioPlayer.setVolume(volume);

3.2 使用just_audio实现播放player

这里通过player来获取SDAudioPlayerState状态，控制音频的暂停音频设置音量等操作

import 'package:flutter_app/manager/logger_manager.dart';
import 'package:just_audio/just_audio.dart';// 播放回调
typedef SDAudioPlayerCallBack = void Function(SDAudioPlayerState state, SDAudioPlayerError? error);// 播放音频的状态
enum SDAudioPlayerState {idle, // 默认loading, // 加载中buffering, // 缓存中ready, // 可播放completed, // 播放完成
}// 播放音频出现错误
class SDAudioPlayerError {String? message;
}// 定义优先级的类
class SDMusicConfig {// 音频文件地址late String audioUrl = '';late bool runLoop = false; // 是否循环播放// 构造函数SDMusicConfig(this.audioUrl, this.audioPriority, this.runLoop);
}// 播放音频文件
class SDMusicPlayer {// 音频播放late AudioPlayer _audioPlayer;// 优先级late SDMusicConfig _musicConfig;late bool _playing = false; // 是否正在播放late SDAudioPlayerState _playerState = SDAudioPlayerState.idle; // 状态late SDAudioPlayerCallBack? _playerCallBack;SDMusicPlayer(this._audioPlayer, this._musicConfig){setAudioUrl(this._musicConfig.audioUrl);openPlayCallBack((state, error) {});}SDMusicConfig getMusicConfig() {return _musicConfig;}void openPlayCallBack(SDAudioPlayerCallBack playerCallBack) {_playerCallBack = playerCallBack;_audioPlayer.playerStateStream.listen((state) {_playing = state.playing;switch(state.processingState) {case ProcessingState.idle: {_playerState = SDAudioPlayerState.idle;break;}case ProcessingState.loading: {_playerState = SDAudioPlayerState.loading;break;}case ProcessingState.buffering: {_playerState = SDAudioPlayerState.buffering;break;}case ProcessingState.ready: {_playerState = SDAudioPlayerState.ready;break;}case ProcessingState.completed: {_playerState = SDAudioPlayerState.completed;if (_musicConfig.runLoop == true) {// 循环播放的时候seek(Duration.zero);play();} else {stop();}break;}default:}if (_playerCallBack != null) {_playerCallBack!(_playerState, null);}});}// var duration = await player.setUrl('https://foo.com/bar.mp3');Future<void> setAudioUrl(String url) async {SDAudioPlayerError? error;if (url.isNotEmpty) {// Set the audio source but manually load audio at a later point.try {_audioPlayer.setUrl(url, preload: true);// Acquire platform decoders and start loading audio.var duration = await _audioPlayer.load();print("url：${url} duration：${duration}");} on PlayerException catch (e) {// iOS/macOS: maps to NSError.code// Android: maps to ExoPlayerException.type// Web: maps to MediaError.code// Linux/Windows: maps to PlayerErrorCode.indexprint("SDAudioPlayer Error code: ${e.code}");// iOS/macOS: maps to NSError.localizedDescription// Android: maps to ExoPlaybackException.getMessage()// Web/Linux: a generic message// Windows: MediaPlayerError.messageprint("SDAudioPlayer Error message: ${e.message}");error = SDAudioPlayerError();error.message = e.message;} on PlayerInterruptedException catch (e) {// This call was interrupted since another audio source was loaded or the// player was stopped or disposed before this audio source could complete// loading.LoggerManager().debug("SDAudioPlayer Connection aborted: ${e.message}");error = SDAudioPlayerError();error.message = e.message;} catch (e) {// Fallback for all errorsprint("e: ${e}");error = SDAudioPlayerError();error.message = e.toString();}} else {error = SDAudioPlayerError();error.message = '播放地址不能为空';}if (_playerCallBack != null) {_playerCallBack!(_playerState, error);}}void play() async {// Usually you don't want to wait for playback to finish.if (_musicConfig.audioUrl != null && _musicConfig.audioUrl.isNotEmpty) {if (_playing == false) {// 正在播放await _audioPlayer.play();}}}void pause() async {if (_musicConfig.audioUrl != null && _musicConfig.audioUrl.isNotEmpty) {await _audioPlayer.pause();}}void stop() async {if (_musicConfig.audioUrl != null && _musicConfig.audioUrl.isNotEmpty) {await _audioPlayer.pause();await _audioPlayer.seek(Duration.zero);}}void seek(Duration position) async {if (_musicConfig.audioUrl != null && _musicConfig.audioUrl.isNotEmpty) {await _audioPlayer.seek(position);}}void setVolume(double volume) async {if (_musicConfig.audioUrl != null && _musicConfig.audioUrl.isNotEmpty) {await _audioPlayer.setVolume(volume);}}// 不需要该播放器，则需要调用该方法void dispose() async {await _audioPlayer.dispose();}
}

四、小结

flutter开发实战-just_audio实现播放音频暂停音频设置音量等。
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