Javascript TypeError:app.use()需要一个中间件函数
每次我尝试在添加用户后运行应用程序时,都会出现类似这样的错误Javascript TypeError:app.use()需要一个中间件函数,javascript,node.js,Javascript,Node.js,每次我尝试在添加用户后运行应用程序时,都会出现类似这样的错误 C:\Users\adity\Desktop\thinkster\medium-api\node_modules\express\lib\application.js:210 throw new TypeError('app.use() requires a middleware function') ^ TypeError: app.use() requires a middleware function
C:\Users\adity\Desktop\thinkster\medium-api\node_modules\express\lib\application.js:210
throw new TypeError('app.use() requires a middleware function')
^
TypeError: app.use() requires a middleware function
at Function.use (C:\Users\adity\Desktop\thinkster\medium-api\node_modules\express\lib\application.js:210:11)
at Object.<anonymous> (C:\Users\adity\Desktop\thinkster\medium-api\app.js:15:5)
at Module._compile (internal/modules/cjs/loader.js:689:30)
at Object.Module._extensions..js (internal/modules/cjs/loader.js:700:10)
at Module.load (internal/modules/cjs/loader.js:599:32)
at tryModuleLoad (internal/modules/cjs/loader.js:538:12)
at Function.Module._load (internal/modules/cjs/loader.js:530:3)
at Function.Module.runMain (internal/modules/cjs/loader.js:742:12)
at startup (internal/bootstrap/node.js:283:19)
at bootstrapNodeJSCore (internal/bootstrap/node.js:743:3)
[nodemon] app crashed - waiting for file changes before starting...
routes/index.js
routes/api/index.js
routes/api/users.js
我发现了一个名为realworld.io的网站,我正在遵循一种制作nodejsapi的方法,在这里我每次都会被卡住。我找不到问题所在。代码app.use('./routes')您的app.js
中的code>不正确(只有一个字符串参数,它违反了app.use()
)
要正确定义“路由”,代码如下所示:
// app.js
const app = express();
const routes = require('./routes');
app.use('/', routes);
@Leegodard如果app.use
接受一个参数,并且该参数是回调函数,则该参数有效。但是,如果一个参数是字符串,而不是函数,那么它是无效的
const express = require('express');
const router = express.Router();
router.use('/api', require('./api'));
module.exports = router;
const express = require('express');
const router = express.Router();
router.use('/', require('./users'));
module.exports = router;
const express = require('express');
const router = express.Router();
router.get('/users', (req, res) => res.send('Hello world'));
module.exports = router;
// app.js
const app = express();
const routes = require('./routes');
app.use('/', routes);