koa-router错误 TypeError: middleware must be a function!

koa-router使用错误 TypeError: middleware must be a function!

  const Koa = require('koa');
  const router = require('koa-router');
  const app = new Koa();
  const main = ctx => {
      ctx.response.body = 'This is homepage';
  };
  const about = ctx => {
      ctx.response.type = 'html';
      ctx.response.body = '
This is about page!
'
  };
  app.use(router.get('/', main));
  app.use(router.get('/about', about));
  app.listen(3000);

运行代码 报错如下：

if (typeof fn !== ‘function’) throw new TypeError(‘middleware must be a function!’);
TypeError: middleware must be a function!

解决：

  const Koa = require('koa');
  const router = require('koa-router')(); // 引入实例化路由 或者 const router = new Router();
  
  const app = new Koa();
  const main = ctx => {
      ctx.response.body = 'This is homepage';
  };
  const about = ctx => {
      ctx.response.type = 'html';
      ctx.response.body = '
This is about page!
'
  };

  router.get('/', main);
  router.get('/about', about)

  app.use(router.routes()); // 启动路由
  app.listen(3000);

结果：