我已经使用Node/Express创建了一个小API,并试图使用Angularjs拉数据,但由于我的html页面在localhost:8888和节点API在端口3000上监听下运行,我得到了No 'Access-Control-Allow-Origin'。我尝试使用node-http-proxy和Vhosts Apache,但没有太多成功,请参阅下面的完整错误和代码。

XMLHttpRequest无法加载localhost:3000。被请求的资源上没有'Access-Control-Allow-Origin'标头。因此,不允许访问Origin 'localhost:8888'。”

// Api Using Node/Express    
var express = require('express');
var app = express();
var contractors = [
    {   
     "id": "1", 
        "name": "Joe Blogg",
        "Weeks": 3,
        "Photo": "1.png"
    }
];

app.use(express.bodyParser());

app.get('/', function(req, res) {
  res.json(contractors);
});
app.listen(process.env.PORT || 3000);
console.log('Server is running on Port 3000')

角码

angular.module('contractorsApp', [])
.controller('ContractorsCtrl', function($scope, $http,$routeParams) {

   $http.get('localhost:3000').then(function(response) {
       var data = response.data;
       $scope.contractors = data;
   })

HTML

<body ng-app="contractorsApp">
    <div ng-controller="ContractorsCtrl"> 
        <ul>
            <li ng-repeat="person in contractors">{{person.name}}</li>
        </ul>
    </div>
</body>

当前回答

/** * Allow cross origin to access our /public directory from any site. * Make sure this header option is defined before defining of static path to /public directory */ expressApp.use('/public',function(req, res, next) { res.setHeader("Access-Control-Allow-Origin", "*"); // Request headers you wish to allow res.setHeader("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type, Accept"); // Set to true if you need the website to include cookies in the requests sent res.setHeader('Access-Control-Allow-Credentials', true); // Pass to next layer of middleware next(); }); /** * Server is about set up. Now track for css/js/images request from the * browser directly. Send static resources from "./public" directory. */ expressApp.use('/public', express.static(path.join(__dirname, 'public'))); If you want to set Access-Control-Allow-Origin to a specific static directory you can set the following.

其他回答

另一种方法是简单地添加头到你的路由:

router.get('/', function(req, res) {
    res.setHeader('Access-Control-Allow-Origin', '*');
    res.setHeader('Access-Control-Allow-Methods', 'GET, POST, OPTIONS, PUT, PATCH, DELETE'); // If needed
    res.setHeader('Access-Control-Allow-Headers', 'X-Requested-With,content-type'); // If needed
    res.setHeader('Access-Control-Allow-Credentials', true); // If needed

    res.send('cors problem fixed:)');
});

这对我很管用。

app.get('/', function (req, res) {

    res.header("Access-Control-Allow-Origin", "*");
    res.send('hello world')
})

你可以根据自己的需要改变*。希望这能有所帮助。

接受的答案是好的,如果你喜欢更短的东西,你可以使用一个插件称为cors可用的Express.js。

对于这种特殊的情况,使用起来很简单:

var cors = require('cors');

// use it before all route definitions
app.use(cors({origin: 'http://localhost:8888'}));

(您可能需要使用127.0.0.1而不是localhost。)

请求源需要与允许的源相匹配,你也可以有多个:

app.use(
  cors({origin: ['http://localhost:8888', 'http://127.0.0.1:8888']})
);

我们将看看前两个答案是否接受我的编辑,但很可能您必须添加或使用127.0.0.1而不是localhost。

使用cors包,你甚至可以使用多个允许的来源:

app.use(
  cors({ origin: ["http://localhost:8888", "http://127.0.0.1:8888"] })
);

如果您希望允许任何内容,则可以使用origin:“*”。

要了解更多信息,请查看Web Dev Simplified的教程。

在NODEJ Restful api的app.js中增加如下代码,以避免在angular 6或其他框架中出现“Access-Control-Allow-Origin”错误

var express = require('express');
var app = express();

var cors = require('cors');
var bodyParser = require('body-parser');

//enables cors
app.use(cors({
  'allowedHeaders': ['sessionId', 'Content-Type'],
  'exposedHeaders': ['sessionId'],
  'origin': '*',
  'methods': 'GET,HEAD,PUT,PATCH,POST,DELETE',
  'preflightContinue': false
}));