Node.js 无法进入Express-NodeJS

我创建了一个express项目，但是我用命令

npm install

安装了模块，但是当我运行

node app.js

时，我无法获得foo，有人能帮我吗

错误：

Error: Failed to lookup view "error" in views directory "C:\Users\Jack\Desktop\demo\views"
   at EventEmitter.app.render (C:\Users\Jack\Desktop\demo\node_modules\express\lib\application.js:555:17)
   at ServerResponse.res.render (C:\Users\Jack\Desktop\demo\node_modules\express\lib\response.js:938:7)
   at C:\Users\Jack\Desktop\demo\app.js:55:7
   at Layer.handle_error (C:\Users\Jack\Desktop\demo\node_modules\express\lib\router\layer.js:58:5)
   at trim_prefix (C:\Users\Jack\Desktop\demo\node_modules\express\lib\router\index.js:300:13)
   at C:\Users\Jack\Desktop\demo\node_modules\express\lib\router\index.js:270:7
   at Function.proto.process_params (C:\Users\Jack\Desktop\demo\node_modules\express\lib\router\index.js:321:12)
   at IncomingMessage.next (C:\Users\Jack\Desktop\demo\node_modules\express\lib\router\index.js:261:10)
   at fn (C:\Users\Jack\Desktop\demo\node_modules\express\lib\response.js:933:25)
   at EventEmitter.app.render (C:\Users\Jack\Desktop\demo\node_modules\express\lib\application.js:557:14)

和app.js：

var express = require('express');
var path = require('path');
var favicon = require('serve-favicon');
var logger = require('morgan');
var cookieParser = require('cookie-parser');
var bodyParser = require('body-parser');

var routes = require('./routes/index');
var users = require('./routes/users');

var app = express();

// view engine setup
app.set('views', path.join(__dirname, 'views'));
app.set('view engine', 'ejs');

// uncomment after placing your favicon in /public
//app.use(favicon(__dirname + '/public/favicon.ico'));
app.use(logger('dev'));
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: false }));
app.use(cookieParser());
app.use(express.static(path.join(__dirname, 'public')));

app.use('/', routes);
app.use('/users', users);



// catch 404 and forward to error handler
app.use(function(req, res, next) {
  var err = new Error('Not Found');
  err.status = 404;
  next(err);
});

// error handlers

// development error handler
// will print stacktrace
if (app.get('env') === 'development') {
  app.use(function(err, req, res, next) {
    res.status(err.status || 500);
    res.render('error', {
      message: err.message,
      error: err
    });
  });
}

// production error handler
// no stacktraces leaked to user
app.use(function(err, req, res, next) {
  res.status(err.status || 500);
  res.render('error', {
    message: err.message,
    error: {}
  });
});

app.get('/foo', function (req, res) {
    res.send('Hello World!');
});

module.exports = app;

var port=3000;
var host='localhost';
app.listen(port, host);

console.log('Check url --> ' + host + ':' + port);

---

这里有什么问题？我安装了运行app.js所需的所有模块，但它不起作用，请帮助我，我如何解决此问题？

缺少错误视图，问题不是express，而是您正在运行的示例

在文件夹视图中创建名为

error.ejs的文件

error.ejs

<h1><%= message %></h1>
<h2><%= error.status %></h2>
<pre><%= error.stack %></pre>



但要让应用程序在完成所有工作、创建的每个文件和文件夹体系结构后运行，您应该使用：



经由
对于找不到的404：

添加到视图文件夹中。它将允许你有每一个错误

对于您的/foo路由，我刚刚看到该路由位于404未找到中间件之下！这意味着它永远不会走这条路线。您应该将所有路由写入
routes/
文件夹的文件中

嘿正如你所说，我创建了一个文件error.ejs，但是错误仍然是“找不到”的，你是在文件夹视图中创建的吗？它应该位于：
C:\Users\Jack\Desktop\demo\views\error.ejs
C:\Users\Jack\Desktop\demo\app.js:32:13在Layer.handle[作为handle\u请求]（C:\Users\Jack\Desktop\demo\node\modules\express\lib\router\Layer.js:82:5）的trim\u前缀处（C:\Users\Jack\Desktop\demo\node\u modules\express\lib\router\index.js:302:13）在C:\Users\Jack\Desktop\demo\node\u modules\express\lib\router\index.js:270:7在视图文件夹中的Function.proto.process\u paramsyeah！你可以在你的
app.js
代码中看到它，这意味着你试图访问一个不存在的页面。你只有
app.js
文件吗？没有其他视图吗？我刚刚看到路由是不存在的R 404找不到中间件！这意味着它将永远不会到达路径。thnx伙计，这是工作：）！完美的很高兴帮助你！
var express = require('express');
var path = require('path');
var favicon = require('serve-favicon');
var logger = require('morgan');
var cookieParser = require('cookie-parser');
var bodyParser = require('body-parser');

var routes = require('./routes/index');
var users = require('./routes/users');

var app = express();

// view engine setup
app.set('views', path.join(__dirname, 'views'));
app.set('view engine', 'ejs');

// uncomment after placing your favicon in /public
//app.use(favicon(__dirname + '/public/favicon.ico'));
app.use(logger('dev'));
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: false }));
app.use(cookieParser());
app.use(express.static(path.join(__dirname, 'public')));

app.use('/', routes);
app.use('/users', users);

app.get('/foo', function (req, res) {
    res.send('Hello World!');
});

// catch 404 and forward to error handler
app.use(function(req, res, next) {
  var err = new Error('Not Found');
  err.status = 404;
  next(err);
});

// error handlers

// development error handler
// will print stacktrace
if (app.get('env') === 'development') {
  app.use(function(err, req, res, next) {
    res.status(err.status || 500);
    res.render('error', {
      message: err.message,
      error: err
    });
  });
}

// production error handler
// no stacktraces leaked to user
app.use(function(err, req, res, next) {
  res.status(err.status || 500);
  res.render('error', {
    message: err.message,
    error: {}
  });
});

module.exports = app;

var port=3000;
var host='localhost';
app.listen(port, host);

console.log('Check url --> ' + host + ':' + port);