将文件从Angular发送到Node Express

<form (submit)="uploadFile($event)">
  <input type="file" (change)="onFileSelected($event)">
  <button type="submit">上传文件</button>
</form>

import { Component } from '@angular/core';
import { HttpClient } from '@angular/common/http';

@Component({
  selector: 'app-file-upload',
  templateUrl: './file-upload.component.html',
  styleUrls: ['./file-upload.component.css']
})
export class FileUploadComponent {
  selectedFile: File | null = null;

  constructor(private http: HttpClient) { }

  onFileSelected(event: any) {
    this.selectedFile = event.target.files[0];
  }

  uploadFile(event: any) {
    event.preventDefault();
    if (this.selectedFile) {
      const formData = new FormData();
      formData.append('file', this.selectedFile);

      this.http.post('/api/upload', formData).subscribe(
        (response) => {
          console.log('文件上传成功');
        },
        (error) => {
          console.error('文件上传失败', error);
        }
      );
    }
  }
}

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

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

app.post('/api/upload', upload.single('file'), (req, res) => {
  const file = req.file;
  // 对上传的文件进行处理，例如保存到服务器的文件系统中、将文件信息存储到数据库中等
  res.send('文件上传成功');
});

app.listen(3000, () => {
  console.log('服务器已启动');
});