NodeJS中如何等待Microsoft SpeechRecognizer异步函数并保存回调结果

问题场景 #

尝试在Microsoft SpeechRecognizer异步方法的回调中存储语音识别结果，即使添加了async/await关键字，最后一行console.log仍会在语音识别完成前执行，无法获取正确结果。

问题原因 #

recognizeOnceAsync是基于回调函数的异步API，并非Promise。你的fromFile函数虽然标记了async，但内部没有等待异步回调完成就直接返回了初始值outputText，导致await无法捕获异步操作的结果。

修改后的代码 #

const fs = require("fs");
const sdk = require("microsoft-cognitiveservices-speech-sdk");

// 需要设置环境变量 SPEECH_KEY 和 SPEECH_REGION
const speechConfig = sdk.SpeechConfig.fromSubscription(process.env.SPEECH_KEY, process.env.SPEECH_REGION);
speechConfig.speechRecognitionLanguage = "en-US";

function fromFile() {
    // 将基于回调的API包装成Promise
    return new Promise((resolve) => {
        let audioConfig = sdk.AudioConfig.fromWavFileInput(fs.readFileSync("YourAudioFile.wav"));
        let speechRecognizer = new sdk.SpeechRecognizer(speechConfig, audioConfig);
        
        speechRecognizer.recognizeOnceAsync(result => {
            let outputText = "";
            switch (result.reason) {
                case sdk.ResultReason.RecognizedSpeech:
                    outputText = `RECOGNIZED: Text=${result.text}`;
                    break;
                case sdk.ResultReason.NoMatch:
                    outputText = "NOMATCH: Speech could not be recognized.";
                    break;
                case sdk.ResultReason.Canceled:
                    const cancellation = sdk.CancellationDetails.fromResult(result);
                    outputText = `CANCELED: Reason=${cancellation.reason}`;

                    if (cancellation.reason == sdk.CancellationReason.Error) {
                        outputText = `CANCELED: ErrorCode=${cancellation.errorCode}`;
                        outputText += `\nCANCELED: ErrorDetails=${cancellation.errorDetails}`;
                        outputText += "\nCANCELED: Did you set the speech resource key and region values?";
                    }
                    break;
            }
            speechRecognizer.close();
            resolve(outputText); // 回调完成后返回结果
        });
    });
}

// 用自执行async函数包裹，确保await正常运行
(async () => {
    let responseMsg = await fromFile();
    console.log(responseMsg);
})();

关键修改点 #

• 将fromFile改为返回Promise对象，把异步回调逻辑包裹在Promise内部，让await能够等待异步操作完成
• 在recognizeOnceAsync的回调中，通过resolve(outputText)将识别结果传递出去
• 修复了原代码中错误的cancellation.ErrorCode（应为小写errorCode），并调整错误信息的拼接方式，避免内容被覆盖
• 用自执行async函数包裹调用逻辑，兼容不支持顶层await的运行环境

内容的提问来源于stack exchange，提问作者Nicholas Drogo