如何使用express后台和react-native上传音频文件？

const express = require('express');
const multer = require('multer');

const app = express();
const upload = multer({ dest: 'uploads/' });

app.post('/upload', upload.single('audio'), (req, res) => {
  // 处理上传的音频文件
  const file = req.file;
  // 其他处理逻辑
  res.send('File uploaded successfully');
});

app.listen(3000, () => {
  console.log('Server is running on port 3000');
});

const uploadAudio = async (audioFile) => {
  const formData = new FormData();
  formData.append('audio', {
    uri: audioFile.uri,
    type: 'audio/mpeg',
    name: 'audio.mp3',
  });

  try {
    const response = await fetch('http://your-backend-api/upload', {
      method: 'POST',
      body: formData,
    });
    const result = await response.text();
    console.log(result);
  } catch (error) {
    console.error(error);
  }
};

import DocumentPicker from 'react-native-document-picker';

const pickAudio = async () => {
  try {
    const res = await DocumentPicker.pick({
      type: [DocumentPicker.types.audio],
    });
    uploadAudio(res);
  } catch (error) {
    console.error(error);
  }
};