Question

我与PayPal-node-SDK npm模块真的很挣扎。它无法将我重定向到paypal页面而错误Failed to load https://www.sandbox.paypal.com/cgi-bin/webscr?cmd=_express-checkout&token=******: Response to preflight request doesn't pass access control check: No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'http://localhost:3000' is therefore not allowed access.而且我在这个世界上读到了这个问题，但是我找不到它的修复方法。所以我正在使用webpack dev服务器对FE部分的反应，我有node.js / express api，这使我连接到paypal sdk。在我的代码中，您可以看到＆＃34; Access-Control-Allow-Origin＆＃34;是允许的，但我仍然有CORS错误。这是我对webpack dev服务器的配置：

＆＃13;

    devServer: {
        contentBase: Path.join(__dirname, './dist'),
        historyApiFallback: true,
        port: 3000,
        proxy: {
            "/api/*": { target: 'http://localhost:5000', secure: false, changeOrigin: true }
        },
        headers: {
            "Access-Control-Allow-Origin": "*",
            "Access-Control-Allow-Methods": "GET, POST, PUT, DELETE, PATCH, OPTIONS",
            "Access-Control-Allow-Headers": "X-Requested-With, content-type, Authorization"
        }
    }

＆＃13;

这是我的node.js api：

＆＃13;

const express = require('express');
const cors = require('cors')
const paypal = require('paypal-rest-sdk');

// Paypal module configuration
paypal.configure({
  'mode': 'sandbox', //sandbox or live
  'client_id': '*********',
  'client_secret': '**********'
});

const app = express();
app.use(cors());

app.post('/api/paypal-payment', (req, res) => {
        var create_payment_json = {
          "intent": "sale",
          "payer": {
            "payment_method": "paypal"
          },
          "redirect_urls": {
            "return_url": "http://localhost:3000/paypal/success",
            "cancel_url": "http://localhost:3000/paypal/cancel"
          },
          "transactions": [{
            "item_list": {
              "items": [{
                "name": "Some Name",
                "sku": "some-sku",
                "price": "1",
                "currency": "USD",
                "quantity": 1
              }]
            },
            "amount": {
              "currency": "USD",
              "total": "1"
            },
            "description": "Some Description"
          }]
        };

        // Make the payment to paypal with the parameters added above
        paypal.payment.create(create_payment_json, function (error, payment) {
          if (error) {
            console.log('error', error);
          } else {
            console.log(payment);
            for (let i = 0; i < payment.links.length; i++) {
              if (payment.links[i].rel === 'approval_url') {
                res.redirect(payment.links[i].href);
              }
            }
          }
        });
    }
  );

const PORT = process.env.PORT || 5000;
app.listen(PORT);

＆＃13;

这是我对API的axios请求：

＆＃13;

export const handlePayment = (months) => {
  return function (dispatch) {
    axios.post('/api/paypal-payment, {
      headers: {
        'Access-Control-Allow-Origin': '*',
      }
    })
      .then(res => dispatch({ type: FETCH_USER, payload: res.data }))
      .catch(error => console.log('error', error));
  }
}

＆＃13;

我尝试了一切，但没有运气，所以每个建议都会受到赞赏。我有什么想法可以解决这个CORS问题？谢谢你们！

Answer 1

CORS过于参与此处，首先axios会拦截CORS请求，然后服务器应该允许来源。您可以查看Network的{{1}}模块中的哪个部分。

允许axios Developer Tools请求

CORS

Answer 2

如果您使用的是Chrome，请尝试添加此插件here 它允许您通过在请求中的标题中添加*来绕过cors检查。

希望这有帮助！

localhost上的CORS问题

2 个答案: