vue node 实现文件的分片上传

以下是一个简单的示例代码，演示了如何使用Node.js的Koa2框架结合Vue3实现文件的分片上传：

在服务器端（Node.js + Koa2）：

```javascript
const Koa = require('koa');
const Router = require('koa-router');
const bodyParser = require('koa-bodyparser');
const fs = require('fs');

const app = new Koa();
const router = new Router();

// 设置中间件
app.use(bodyParser());

// 处理文件分片上传
router.post('/upload', async (ctx) => {
  const { filename, index, total, data } = ctx.request.body;

  const uploadPath = `./uploads/${filename}`;
  const writeStream = fs.createWriteStream(uploadPath, { flags: 'a' });

  // 将分片数据追加写入文件
  writeStream.write(Buffer.from(data, 'base64'));

  // 如果是最后一个分片，则关闭写入流，表示上传完成
  if (index === total - 1) {
    writeStream.end();

    ctx.body = {
      message: 'Upload complete',
      file: uploadPath,
    };
  } else {
    ctx.body = {
      message: 'Upload in progress',
    };
  }
});

app.use(router.routes()).use(router.allowedMethods());

app.listen(3000, () => {
  console.log('Server is running on http://localhost:3000');
});

在客户端（Vue3）：