在鸿蒙Next系统中，AVPlayer为开发者提供了强大的音频播放功能。以下将详细介绍如何使用AVPlayer来实现音频播放。
播放状态变化示意图
file
基本使用步骤
-
创建AVPlayer实例：通过
media.createAVPlayer()方法创建AVPlayer实例，用于控制音频的播放。示例代码如下：
async createAVPlayerInstance() {
const avPlayer = await media.createAVPlayer(); // 异步
return avPlayer;
}
-
设置播放源：指定本地 rawFile 路径，如
test.mp3
async setSourcePath(path: string) {
setTimeout(async () => {
if (!this.checkNull()) {
try {
let context = getContext(this) as common.UIAbilityContext;
let fileDescriptor = await context.resourceManager.getRawFd(path);
let fileFd: number = JSON.parse(JSON.stringify(fileDescriptor))['fd']
let fileOffset: number = JSON.parse(JSON.stringify(fileDescriptor))['offset']
this.avFileDescriptor = { fd: fileFd, offset: fileOffset, length: -1 };
this.avPlayer!.fdSrc = this.avFileDescriptor;
} catch (err) {
console.info('Set Url failed : ' + JSON.stringify(err))
}
}
}, 500)
}
-
监听状态变化：监听
stateChange事件来了解播放器的状态，从而做出相应操作。示例代码如下：
/**
* avplayer回调
*/
private setAVPlayerCallback() {
if (this.checkNull()) {
return
}
// seek操作结果回调
this.avPlayer!.on('seekDone', (seekDoneTime) => {
console.info(`AVPlayer seek succeeded, seek time is ${seekDoneTime}`);
})
// 音量变化回调
this.avPlayer!.on('volumeChange', (volume) => {
console.info(`volumeChange called, and new volume is :${volume}`);
})
// 音频总时长
this.avPlayer!.on('durationUpdate', (duration) => {
console.info(`durationUpdate :${duration}`);
})
// 当前播放进度
this.avPlayer!.on('timeUpdate', (time) => {
let now = Math.floor(time/1000)
if (this.process != now) {
console.info(`timeUpdate :${now}`);
}
this.process = now
})
// error回调监听函数,当avPlayer在操作过程中出现错误时调用reset接口触发重置流程
this.avPlayer!.on('error', (err) => {
console.error(`Invoke avPlayer failed, code is ${err.code}, message is ${err.message}`);
this.avPlayer!.reset(); // 调用reset重置资源，触发idle状态
})
// 状态机变化回调函数
this.avPlayer!.on('stateChange', async (state, reason) => {
switch (state) {
case 'idle': // 成功调用reset接口后触发该状态机上报
console.info('AVPlayer state idle called.');
this.avPlayer!.release(); // 调用release接口销毁实例对象
break;
case 'initialized': // avplayer 设置播放源后触发该状态上报
console.info('AVPlayer state initialized called.');
this.avPlayer!.prepare().then(() => {
console.info('AVPlayer prepare succeeded.');
}, () => {
console.error(`Invoke prepare failed, code is`);
});
break;
case 'prepared': // prepare调用成功后上报该状态机
console.info('AVPlayer state prepared called.');
this.avPlayer!.loop = this.loop
this.avPlayer!.setVolume(this.volume)
if (this.autoPlay) {
this.avPlayer!.play(); // 调用播放接口开始播放
}
break;
case 'playing': // play成功调用后触发该状态机上报
console.info('AVPlayer state playing called.');
break;
case 'paused': // pause成功调用后触发该状态机上报
console.info('AVPlayer state paused called.');
break;
case 'completed': // 播放结束后触发该状态机上报
console.info('AVPlayer state completed called.');
if (this.loop == true) {
this.avPlayer!.seek(0)
this.avPlayer!.play()
}
break;
case 'stopped': // stop接口成功调用后触发该状态机上报
console.info('AVPlayer state stopped called.');
break;
case 'released':
console.info('AVPlayer state released called.');
break;
default:
console.info('AVPlayer state unknown called.');
break;
}
})
}
-
控制音频播放：可以调用
play()、pause()、stop()、seek()等方法对音频进行播放、暂停、停止、跳转等操作。示例代码如下：
play() {
if (this.checkNull()) {
this.autoPlay = true
return
}
this.avPlayer!.play().then(() => {
console.info('Play success')
}).catch((err: BusinessError) => {
console.info('Play failed : ' + JSON.stringify(err))
})
}
pause() {
if (this.checkNull()) {
this.autoPlay = false
return
}
this.avPlayer!.pause().then(() => {
console.info('Pause success')
}).catch((err: BusinessError) => {
console.info('Pause failed : ' + JSON.stringify(err))
})
}
release() {
if (this.checkNull()) {
this.autoPlay = false
return
}
this.avPlayer!.release().then(() => {
console.info('Release success')
setTimeout(() => {
}, 500)
}).catch((err: BusinessError) => {
console.info('Release failed : ' + JSON.stringify(err))
})
}
setVolume(volume: number) {
console.info(`setVolume ${volume}`)
this.volume = volume
if (this.checkNull()) {
return
}
this.avPlayer!.setVolume(volume)
}
setLoop() {
console.info('setLoop')
this.loop = true
if (this.checkNull()) {
return
}
this.avPlayer!.loop = true
}
设置音量和循环播放时需要在状态 prepared 后调用，否则会报错
Invoke avPlayer failed, code is 5400102, message is Operate Not Permit: current state is not prepared/playing/paused/completed, unsupport loop operation
-
释放资源：当音频播放完成或者不再需要播放时，调用
release()方法释放资源，避免内存泄漏。示例代码如下：
async function releasePlayer(avPlayer) {
await avPlayer.release();
}
注意事项
-
权限申请：如果要访问在线媒体资源，需要在配置文件中申请
ohos.permission.INTERNET权限。 - 资源格式：确保音频文件格式与鸿蒙系统支持的格式兼容，以避免无法播放的情况。
-
异常处理：在播放过程中可能会遇到网络中断、文件损坏等异常情况，需要添加异常处理逻辑，如监听
error事件来进行相应处理。
希望通过以上介绍，能帮助开发者在鸿蒙Next应用开发中熟练使用AVPlayer实现音频播放功能，为用户带来更好的音频体验。
本文由博客一文多发平台 OpenWrite 发布！
