我有这个反应应用程序，我正在使用useState Hook更新useEffect内的状态： import React, {useState, useEffect} from 'react'; export default function App() { const {userData, setUserData} = useState({ token : undefined, user: undefined }); useEffect(() =>{ ...

我在useEffect钩子上遇到问题，显然，它没有像以前那样呈现，因为我的cardArticle无法正确记录日志，它只能连接las数组，仅此而已。这是代码： const [articles, setArticles] = useState([]); const [cardArticle, setCardArticle] = useState([]); useEffect(() => { setArticulos(shopArticles); }, []); useEffect...

我正在尝试将基于此类的类转换为基于功能组件的类 这是实际的基于类别的代码 import React, { Component } from 'react'; import L from 'leaflet' import { Map, TileLayer, Marker, Popup } from 'react-leaflet'; import './App.css'; // Icon properties var myIcon = L.icon({ iconUrl: 'data:image/png;b...

I am a newbie in React. I created the movie app project using React. and then I have created some additional styling for this project. I want to add a popup window for this project. I wrote some code for this component. But this popup component appears in ...

编辑：将拼接更改为0，以便删除数字，而不是1似乎可以做到。奇怪，因为我怀疑根据所有示例，我已经看到，如果要删除单个元素，则将splice的第二个参数设置为1。 首先，请允许我说我还很陌生。 我在尝试从数据数组中删除元素时遇到问题。我已经添加了useState挂钩，并使用从API返回的数据来填充它，然后我要完成的工作是，当我单击添加按钮时，它应该从模式中删除用户并将其添加到我的教练中模型的总分配用户。 但是，我可以看到它命中了代码，如果注销长度，我可以清楚地看到它确实发生了更改，但是，即使我确实更新了状态，U...

Re-posting a similar question to my last because of a new issue. I'm trying to use context with hooks to manage authentication in my react app. I'm getting the error TypeError: Cannot destructure property 'isAuthenticated' of 'Object(...)(...)' as it is un...

import React, { useState, useEffect } from "react"; import axios from "axios"; import styled from "styled-components"; import Form from "react-bootstrap/Form"; import Col from "react-bootstrap/Col"; import Button from "react-bootstrap/Button"; //import Spi...

I have a <Day/> component which renders a table full of times through the day. Right now I have a handleChange function in the <TableLayout/> which is listening for changes in the text-area. function TableLayout({ sendEventTargetToParent }) { var [amoun...

如果该新信息对象的名称与该状态中的名称相同，则我试图更新状态以包括新的信息对象。例如.... 新信息时： { serviceName: name: A properties:{ cost: 300 service:"Good" } } 匹配现有状态的名称： { serviceName: name: A properties:{ cost: 600 service:"Bad" } } 目的是我可以然后仅合并属性，从而导致：...