React Hook useEffect 缺少依赖项：'fetchData'

Question

谁能帮我解决这个错误？在 useEffect 中，我调用了一个发出请求并将响应插入 redux 状态的函数。

import React, { useEffect, useState } from "react";
import { BrowserRouter as Router, Switch, Route} from "react-router-dom";
import { useDispatch, useSelector } from 'react-redux'
import { actions } from './actions/actions'
import { I18nProvider } from './i18n'
import axios from 'axios'

import Home from './views/home/home';
import Page1 from './views/page1/page1';
import Page2 from './views/page2/page2'
import Page3 from './views/page3/page3'

const App = () => {

  const [isLoading, setIsLoading] = useState(true)

  const localeDefault = useSelector(state => state.audioGuideReducers.lang)

  const dispatch = useDispatch()
  const setDataRedux= (data) => dispatch(actions.setDataRedux(data))

  useEffect(() => {
    fetchData();
  }, []);

  const fetchData = async () => {
    await axios.get('https://link-api.com/alldata')
      .then((response) => {
        setDataRedux(response.data.data)
        setIsLoading(false)
      })
      .catch( (error) => {
        console.log(error.message);
      })
  }

  return (
    <I18nProvider locale={localeDefault}>
      <Router>
        {
          isLoading ?
            <h1> Loading... </h1>
            :
            <Switch>
              <Route path="/page3/:id" component={Page3} />
              <Route path="/page2" component={Page2} />
              <Route path="/page1" component={Page1} />
              <Route path="/" component={Home} />
            </Switch>
        }
      </Router>
    </I18nProvider>
  );
}

export default App

虽然应用程序是“运行”，但我想解决出现的以下警告： “React Hook useEffect 缺少依赖项：'fetchData'。包含它或删除依赖项矩阵 react-hooks/exaustive-deps”

Answer 1

将 fetchData 作为参数传递给 useEffect

 useEffect(() => {
    fetchData();
  }, [fetchData]);

Answer 2

这是因为每当您使用 useEffect 并且如果您使用 useEffect 之外的东西。 UseEffect 需要确定什么时候更新什么时候不更新，这就是为什么你需要在它的依赖项中传递它：

useEffect(() => {
    fetchData();
  }, [fetchData]);

  const fetchData = async () => {
    await axios.get('https://link-api.com/alldata')
      .then((response) => {
        setDataRedux(response.data.data)
        setIsLoading(false)
      })
      .catch( (error) => {
        console.log(error.message);
      })
  }

更好的方法，如果你只需要在 useEffect 里面把 fetchData 放在 useEffect 里面：

const setDataRedux = React.useCallback((data) => dispatch(actions.setDataRedux(data)), [])
useEffect(() => {
    const fetchData = async () => {
    await axios.get('https://link-api.com/alldata')
      .then((response) => {
        setDataRedux(response.data.data)
        setIsLoading(false)
      })
      .catch( (error) => {
        console.log(error.message);
      })
  }
    fetchData();
  }, [setDataRedux]);

React Hook useEffect 缺少依赖项：'fetchData'

React Hook useEffect has a missing dependency: 'fetchData'

javascript

webhooks

reactjs

react-redux

react-hooks