TypeError: Cannot read property '_locals' of undefined

Question

我正在尝试在 ubuntu 16.04 中使用 nodejs，并且我安装了 node 和 npm，但是当我尝试这个时我遇到了这个错误 "TypeError: Cannot read property '_locals' of undefined"：

var express = require("express");
    app = express();
    bodyParser = require("body-parser");
    mongoose = require("mongoose");

app.set("view engine", "ejs");

app.get("/", function(req,res){
    app.render("index");
});

app.listen(3000, function(){
    console.log("Server Started!");
})

它在终端输出：

Server Started!
TypeError: Cannot read property '_locals' of undefined
    at EventEmitter.render (/home/luis/Documents/work/webdevBootcamp/test/node_modules/express/lib/application.js:548:11)
    at /home/luis/Documents/work/webdevBootcamp/test/app.js:9:6
    at Layer.handle [as handle_request] (/home/luis/Documents/work/webdevBootcamp/test/node_modules/express/lib/router/layer.js:95:5)
    at next (/home/luis/Documents/work/webdevBootcamp/test/node_modules/express/lib/router/route.js:131:13)
    at Route.dispatch (/home/luis/Documents/work/webdevBootcamp/test/node_modules/express/lib/router/route.js:112:3)
    at Layer.handle [as handle_request] (/home/luis/Documents/work/webdevBootcamp/test/node_modules/express/lib/router/layer.js:95:5)
    at /home/luis/Documents/work/webdevBootcamp/test/node_modules/express/lib/router/index.js:277:22
    at Function.process_params (/home/luis/Documents/work/webdevBootcamp/test/node_modules/express/lib/router/index.js:330:12)
    at next (/home/luis/Documents/work/webdevBootcamp/test/node_modules/express/lib/router/index.js:271:10)
    at expressInit (/home/luis/Documents/work/webdevBootcamp/test/node_modules/express/lib/middleware/init.js:33:5)
    at Layer.handle [as handle_request] (/home/luis/Documents/work/webdevBootcamp/test/node_modules/express/lib/router/layer.js:95:5)
    at trim_prefix (/home/luis/Documents/work/webdevBootcamp/test/node_modules/express/lib/router/index.js:312:13)
    at /home/luis/Documents/work/webdevBootcamp/test/node_modules/express/lib/router/index.js:280:7
    at Function.process_params (/home/luis/Documents/work/webdevBootcamp/test/node_modules/express/lib/router/index.js:330:12)
    at next (/home/luis/Documents/work/webdevBootcamp/test/node_modules/express/lib/router/index.js:271:10)
    at query (/home/luis/Documents/work/webdevBootcamp/test/node_modules/express/lib/middleware/query.js:44:5)

当我加载 localhost:3000 时，它不会呈现 ejs 文件，也不会让我使用我做的 send() 函数

app.get("/", function(req,res){
    app.send("whatever");
});

它说：

TypeError: app.send is not a function

我确实安装了 express 和 ejs 模块（运行 npm install i -S express ejs mongoose body-parser）

Answer 1

请设置您的视图目录。 example:if 您的索引模板文件在 'src'

app.set('views', __dirname + '/src');

Answer 2

正如@digit 在评论中所说： "You shouldn't call app.send instead res.send. an app is an object for routing http request."

问题是我在做

app.get("/", function(req,res){
    app.send("whatever");
});

而不是

app.get("/", function(req,res){
    res.send("whatever"); // res instead of app
});

TypeError: Cannot read property '_locals' of undefined

TypeError: Cannot read property '_locals' of undefined

javascript

node.js

express

ubuntu-16.04