将表单以外的内容传递给POST请求

fetch('/api/data', {
  method: 'POST',
  headers: {
    'Content-Type': 'application/json'
  },
  body: JSON.stringify({
    name: 'John Doe',
    age: 30
  })
})
.then(response => response.json())
.then(data => console.log(data))
.catch(error => console.error('Error:', error));

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

app.use(express.json());

app.post('/api/data', (req, res) => {
  console.log(req.body);
  res.json({ message: 'Data received' });
});

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

<form id="uploadForm">
  <input type="file" name="file" />
  <button type="submit">Upload</button>
</form>

<script>
document.getElementById('uploadForm').addEventListener('submit', function(event) {
  event.preventDefault();
  const formData = new FormData(this);
  fetch('/api/upload', {
    method: 'POST',
    body: formData
  })
  .then(response => response.json())
  .then(data => console.log(data))
  .catch(error => console.error('Error:', error));
});
</script>

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

const storage = multer.diskStorage({
  destination: function (req, file, cb) {
    cb(null, 'uploads/');
  },
  filename: function (req, file, cb) {
    cb(null, file.originalname);
  }
});

const upload = multer({ storage: storage });

app.post('/api/upload', upload.single('file'), (req, res) => {
  console.log(req.file);
  res.json({ message: 'File uploaded successfully' });
});

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