Question

这是我的App.js文件。我在这里运行查询。
我使用apollo客户端而不是apollo-boost。

import React, { useEffect } from "react";
import { useQuery } from "react-apollo";
import gql from "graphql-tag";
    
const MY_QUERY = gql`
  query {
    getAllSalons {
      id
      displayName
      email
    }
  }
`;
        
const App = (props) => {
  const { data, loading, error } = useQuery(MY_QUERY);
  useEffect(() => console.log("-------", data), [data]);
  useEffect(() => console.log("-------", error), [error]);
  return (
    <div className="App">
      <h1>KOMB COLLECTION</h1>
      {loading ? <h2>Loading...</h2> : <h2>Data :)</h2>}
    </div>
  );
}

这是我在index.js文件中设置apollo客户端的方法
我在阿波罗客户端中设置了身份验证。

这里是所有进口

import ApolloClient from "apollo-client";
import { ApolloProvider } from "react-apollo";
import { createHttpLink } from "apollo-link-http";
import { setContext } from "apollo-link-context";
import { InMemoryCache } from "apollo-cache-inmemory";

我仅通过此端点无法获取错误，但是它可以工作在Postman中可以正常使用，并且另一个端点与此代码配合使用也很好。

const httpLink = createHttpLink({
  uri: "http://13.125.142.93:3001/graphql",
});

const authLink = setContext((_, { headers }) => {
  const token = localStorage.getItem("token");
  return {
    headers: {
      ...headers,
      Authorization: token ? token : "",
    },
  };
});
const client = new ApolloClient({
  link: authLink.concat(httpLink),
  cache: new InMemoryCache(),
});

ReactDOM.render(
  <ApolloProvider client={client}>
    <App />
  </ApolloProvider>,
  document.getElementById("root")
);

我是graphql的新手，不知道如何处理此错误。另外，我也找不到任何文档。

我在控制台上收到此错误

Access to fetch at 'http://13.125.142.93:3001/graphql' from origin
'http://localhost:3000' has been blocked by CORS policy: Response to
preflight request doesn't pass access control check: No
'Access-Control-Allow-Origin' header is present on the requested
resource. If an opaque response serves your needs, set the request's
mode to 'no-cors' to fetch the resource with CORS disabled.

Answer 1

发生此错误是因为后端没有针对cors的配置。在后端配置cors，一切都会正常运行

我收到Newwork错误：每次在Apollo客户端中均无法获取

1 个答案: