javascript - React Ajax 请求给出 CORS 错误但返回数据

Question

我正在尝试发出 GET 请求，通过 POSTMAN 可以正常工作，但在 React 上似乎不起作用。

出于某种原因，尽管存在 CORS 错误，它也会返回数据。如何解决？

API 负载:

index.js(Redux 设置)

import React from 'react';
import ReactDOM from 'react-dom';
import { BrowserRouter as Router } from 'react-router-dom';
import App from './App';

import { Provider } from 'react-redux';
import { createStore, applyMiddleware } from 'redux';
import ReduxPromise from 'redux-promise';
import thunk from 'redux-thunk';

import createHistory from 'history/createBrowserHistory'
import { ConnectedRouter, routerReducer, routerMiddleware, push } from 'react-router-redux'

import {assumeRole} from './libs/awsLib';

import './index.css';

import reducers from './reducers';
import {LOGIN, LOGOUT} from "./actions/UsersActions";
import {api} from "./actions/api";

const history = createHistory();
const myRouterMiddleware = routerMiddleware(history);

const createStoreWithMiddleware = applyMiddleware(ReduxPromise, thunk, myRouterMiddleware)(createStore);

ReactDOM.render(
  <Provider store={createStoreWithMiddleware(reducers)}>
    <ConnectedRouter history={history}>
      <App />
    </ConnectedRouter>
  </Provider>,
  document.getElementById('root')
);

文件列表 reducer

import {GET_DOCUMENTS} from "../actions/index";

export default function(state = [], action) {
    //reducers should return a new object, never mutate the current state

    switch (action.type) {
        case GET_DOCUMENTS:
            return action.payload;
    }

    return state;
}

文件操作

import 'whatwg-fetch'
import {api} from './api';
import config from '../config.js';

export const GET_DOCUMENTS = 'GET_DOCUMENTS';

export function getDocuments() {
    return (dispatch) => {
        const request = api.fetch('warpig/document/?userId='+localStorage.getItem("id")).then((res) => {
            dispatch({
                type: GET_DOCUMENTS,
                payload: {data: res, success: res.status == 200}
            })
        }, (err, data) =>  {
            console.log(err, data);
        });
    }
}

我调用 getDocuments() 的方法

...

    componentDidMount() {
        this.getDocuments();
    }

    getPrograms() {
        this.props.fetchPrograms();
    }
...

function mapDispatchToProps(dispatch) {
    return bindActionCreators({ fetchPrograms, uploads3, login, assignToken, getDocuments }, dispatch);
}

function mapStateToProps({ programs, fileUpload, auth, filesList }) {
    return { programs, fileUpload, auth, filesList };
}

export default connect(mapStateToProps, mapDispatchToProps)(FileUpload)

主要问题是它可以通过 POSTMAN 工作，但当我通过 React 在浏览器上发出 HTTP GET 请求时不起作用，尽管它正在返回数据，那么，可能是什么？

Answer 1

它适用于 POSTMAN，而不是在浏览器中，因为 CORS 。为了解决这个问题，您需要服务器响应数据，让“access-control-allow-origin” header 包含 * 或包含您网站的域名。

另请参阅此 question