ExpressJS：请求已被CORS策略阻止：请求的资源上不存在“ Access-Control-Allow-Origin”标头

Question

在我的浏览器开发人员工具栏中，我收到以下关于POST请求的错误消息：

Access to XMLHttpRequest at 'http://localhost:8000/api/tags/' from origin 'http://localhost:3000' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource.

但是，当我查看server.js时，我却允许访问：

app.prepare().then(() => {
    const server = express();

    server.use(function(req, res, next) {
        res.header("Access-Control-Allow-Origin", "*");
        res.header("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type, Accept");
        next();
    });

有人知道为什么现在阻止它

Answer 1

最好按照以下方式使用“ cors”软件包。

as_adj