reactjs - Firebase 错误 : No firebase app default has been created

Question

我正在使用 react-native 和 redux 制作食品配送应用程序。我想从 firebase 存储中获取数据，为此，我在 中编写了一个函数行动 .js，但每当我运行应用程序时，它都会显示错误Firebase: No Firebase App '[DEFAULT]' has been created - call Firebase App.initializeApp() (app/no-app).这是我用来获取数据的函数
action.js

import firebase from "firebase"
export const ProductDetails = (data) => {
  return {
    type: "PRODUCT_ITEMS",
    payload: {
      data,
    },
  };
};

var db = firebase.firestore();
var docRef = db.collection("Products").doc("Items");
export const FetchItems = () => {
  return async function (dispatch) {
    return await docRef
      .get()
      .then((doc) => {
        if (doc.exists) {
          console.log("Document Data", doc.data());
          dispatch(ProductDetails(doc.data));
        } else {
          console.log("NO such document");
        }
      })
      .catch((error) => {
        console.log(error);
      });
  };
};

这是我的 App.js 文件

import React, { useState } from "react";
import { StyleSheet, Text, View, Dimensions } from "react-native";
import { NavigationContainer } from "@react-navigation/native";
import AppStack from "./components/navigation/AppStack";

import firebase from "firebase";
import {Provider} from "redux"
import store from "./store"

import { useDispatch, useSelector, Provider } from "react-redux";
import store from "./redux/store";
import AppWrapper from "./AppWrapper";

export default function App() {
  
  const firebaseConfig = {
  };
  if (firebase.apps.length === 0) {
    firebase.initializeApp(firebaseConfig);
  }
  return  (
    <Provider store={store}>
      <NavigationContainer>
        <AppStack />
      </NavigationContainer>
    </Provider>
  );;
}

Answer 1

我建议创建一个单独的文件 firebase.js并在初始化后从那里导出 Firebase 服务。
firebase.js

import firebase from 'firebase/app';
import 'firebase/firestore'

const firebaseConfig = {...};

if (!firebase.apps.length) {
  firebase.initializeApp(config);
}

export const auth = firebase.auth();
export const firestore = firebase.firestore()

然后在任何需要它们的地方导入它们:

// App.js for example

import {firestore, auth} from './firebase.js'

//var docRef = firestore.collection("Products").doc("Items");