为什么节点的“fs”模块没有加载？（错误：对象#<Object>没有方法“readFile”）

Question

由于某种原因，我的 Express 服务器无法正确加载文件系统“fs”模块。我正在使用 Angular-fullstack yeoman 生成器。我的系统是 Windows 7，节点版本为 0.10.35，npm 版本为 2.1.18，以及最新版本的 Angular-fullstack。我尝试了各种方法，例如 32 位和 64 位并更新了所有内容。

routes.js（其中有其他可以正常加载的路由）：

'use strict';

var errors = require('./components/errors');
var express = require('express');
var fs = require('fs');

module.exports = function(app) {

    app.route('/pdf/*')
        .get(function(req, res) {
            var pdfPath = app.get('appPath') + '/assets/pdf/test.pdf';
            fs.readfile(pdfPath, function(error, data) {
                res.setHeader('Content-Disposition', 'attachment; filename="test.pdf"');
                res.setHeader('Content-Type', 'application/pdf');
                res.setHeader('Content-Length', data.length);
                res.status(200).end(data, 'binary');
            });
        });

    // All undefined asset or api routes should return a 404
    app.route('/:url(api|auth|components|app|bower_components|assets)/*')
        .get(errors[404]);    

    // All other routes should redirect to the index.html
    app.route('/*')
        .get(function(req, res) {
            res.sendfile(app.get('appPath') + '/index.html');
        });
};

服务器错误：

TypeError: Object #<Object> has no method 'readfile'
    at Object.handle (C:\Projects\policy5\server\routes.js:19:7)
    at next_layer (C:\Projects\policy5\node_modules\express\lib\router\route.js:103:13)
    at Route.dispatch (C:\Projects\policy5\node_modules\express\lib\router\route.js:107:5)
    at c (C:\Projects\policy5\node_modules\express\lib\router\index.js:195:24)
    at Function.proto.process_params (C:\Projects\policy5\node_modules\express\lib\router\index.js:251:12)
    at next (C:\Projects\policy5\node_modules\express\lib\router\index.js:189:19)
    at next (C:\Projects\policy5\node_modules\express\lib\router\index.js:166:38)
    at trim_prefix (C:\Projects\policy5\node_modules\express\lib\router\index.js:228:11)
    at c (C:\Projects\policy5\node_modules\express\lib\router\index.js:198:9)
    at Function.proto.process_params (C:\Projects\policy5\node_modules\express\lib\router\index.js:251:12)
GET /pdf/test.pdf 500 2ms - 934b

Answer 1

它readFile()不是readfile()（大写F与小写f）。