HarmonyOS 鸿蒙Next语音转文字ASR功能如何实现？语音识别开发指南

1. 权限配置

在 module.json5 中添加麦克风权限：

{
  "requestPermissions": [
    {
      "name": "ohos.permission.MICROPHONE",
      "reason": "$string:microphone_permission_reason",
      "usedScene": {
        "abilities": ["EntryAbility"],
        "when": "inuse"
      }
    }
  ]
}

2. 完整实现代码

import { speechRecognizer } from '@kit.CoreSpeechKit'
import { abilityAccessCtrl, Permissions } from '@kit.AbilityKit'
import { BusinessError } from '@kit.BasicServicesKit'

@Entry
@Component
struct ASRPage {
  @State recognizedText: string = ''
  @State isListening: boolean = false
  @State statusText: string = '点击开始录音'

  private asrEngine: speechRecognizer.SpeechRecognitionEngine | null = null
  private sessionId: string = '10000'

  aboutToAppear(): void {
    this.requestPermission()
  }

  aboutToDisappear(): void {
    this.releaseEngine()
  }

  // 请求麦克风权限
  async requestPermission(): Promise<void> {
    const permissions: Permissions[] = ['ohos.permission.MICROPHONE']
    const atManager = abilityAccessCtrl.createAtManager()
    
    try {
      const result = await atManager.requestPermissionsFromUser(
        getContext(this),
        permissions
      )
      if (result.authResults[0] === 0) {
        await this.initASREngine()
      } else {
        this.statusText = '需要麦克风权限'
      }
    } catch (err) {
      console.error('权限请求失败:', err)
    }
  }

  // 初始化语音识别引擎
  async initASREngine(): Promise<void> {
    const extraParams: Record<string, Object> = {
      "locate": "CN",
      "recognizerMode": "short"
    }
    
    const initParams: speechRecognizer.CreateEngineParams = {
      language: 'zh-CN',
      online: 1,  // 1: 在线识别
      extraParams: extraParams
    }
    
    try {
      this.asrEngine = await speechRecognizer.createEngine(initParams)
      this.setListener()
      this.statusText = '准备就绪'
    } catch (err) {
      const error = err as BusinessError
      console.error(`引擎初始化失败: ${error.code} - ${error.message}`)
      this.statusText = '初始化失败'
    }
  }

  // 设置识别回调
  setListener(): void {
    if (!this.asrEngine) return
    
    const listener: speechRecognizer.RecognitionListener = {
      onStart: (sessionId: string, eventMessage: string) => {
        this.isListening = true
        this.statusText = '正在听...'
      },
      onEvent: (sessionId: string, eventCode: number, eventMessage: string) => {
        console.info(`事件: ${eventCode} - ${eventMessage}`)
      },
      onResult: (sessionId: string, result: speechRecognizer.SpeechRecognitionResult) => {
        // 获取识别结果
        if (result.result) {
          this.recognizedText = result.result
        }
        if (result.isFinal) {
          this.statusText = '识别完成'
        }
      },
      onComplete: (sessionId: string, eventMessage: string) => {
        this.isListening = false
        this.statusText = '点击开始录音'
      },
      onError: (sessionId: string, errorCode: number, errorMessage: string) => {
        this.isListening = false
        this.statusText = `错误: ${errorMessage}`
        console.error(`识别错误: ${errorCode} - ${errorMessage}`)
      }
    }
    
    this.asrEngine.setListener(listener)
  }

  // 开始识别
  startRecognition(): void {
    if (!this.asrEngine || this.isListening) return
    
    const recognizerParams: speechRecognizer.StartParams = {
      sessionId: this.sessionId,
      audioInfo: {
        audioType: 'pcm',
        sampleRate: 16000,
        soundChannel: 1,
        sampleBit: 16
      },
      extraParams: {
        "vadBegin": 2000,
        "vadEnd": 3000,
        "maxAudioDuration": 20000
      }
    }
    
    try {
      this.asrEngine.startListening(recognizerParams)
    } catch (err) {
      console.error('开始识别失败:', err)
    }
  }

  // 停止识别
  stopRecognition(): void {
    if (!this.asrEngine || !this.isListening) return
    
    try {
      this.asrEngine.finish(this.sessionId)
    } catch (err) {
      console.error('停止识别失败:', err)
    }
  }

  // 释放引擎
  releaseEngine(): void {
    if (this.asrEngine) {
      try {
        this.asrEngine.shutdown()
        this.asrEngine = null
      } catch (err) {
        console.error('释放引擎失败:', err)
      }
    }
  }

  build() {
    Column({ space: 20 }) {
      // 状态显示
      Text(this.statusText)
        .fontSize(16)
        .fontColor($r('app.color.text_secondary'))
      
      // 识别结果
      Text(this.recognizedText || '识别结果将显示在这里')
        .fontSize(18)
        .fontColor($r('app.color.text_primary'))
        .padding(20)
        .backgroundColor($r('app.color.surface'))
        .borderRadius(12)
        .width('100%')
        .minHeight(120)
      
      // 录音按钮
      Button() {
        Row({ space: 8 }) {
          Image($r('app.media.ic_microphone'))
            .width(24)
            .height(24)
            .fillColor(Color.White)
          Text(this.isListening ? '停止' : '开始录音')
            .fontSize(16)
            .fontColor(Color.White)
        }
      }
      .width(160)
      .height(48)
      .backgroundColor(this.isListening ? '#ef4444' : '#36e27b')
      .borderRadius(24)
      .onClick(() => {
        if (this.isListening) {
          this.stopRecognition()
        } else {
          this.startRecognition()
        }
      })
    }
    .width('100%')
    .height('100%')
    .padding(16)
    .backgroundColor($r('app.color.background'))
  }
}