請求的資源上不存在“Access-Control-Allow-Origin”header。 NodejS Express

Question

我收到此錯誤

(index):1 Access to XMLHttpRequest at 'https://example.com/crm/addlead' from origin 'https://abc.examplehosting.com' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource.

我也在我的 app.js 中添加了這段代碼

app.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();
   

});

請提出可能是什么問題。

Answer 1

您需要安裝cors CORS 。

const cors = require('cors')

var corsOptions = {
  origin: '*',
  optionsSuccessStatus: 200 // some legacy browsers like IE11
}
app.use(cors(corsOptions));

Answer 2

嘗試將cors層添加到您的應用程序中，

npm install --save cors

// In your server file
var cors = require('cors');
...

app.use(cors());

在此處了解有關 cors的更多詳細信息