在组件中添加可选组件的最佳方法是什么?
我有一个这样的:
type Props = {
children: React.Node,
title?: string,
/**May add any component next to the header. Should be inside a fragment. */
headerComponents?: React.Node,
className?: string,
}
export const Content = ({ children, className, title, headerComponents }: Pro
问题
我刚开始做酶和反应测试。我试图让酶与业力和webpack一起工作在一个琐碎的反应部件上。我的问题是包装器上的prop()返回null,我不知道为什么。
Greeter.js
import React from 'react';
/*
* A trivial component we added while trying to get the react testing working
* */
export default class Greeter extends React.Component {
constructor(props) {
super
本质上,我得到了一个不变的违规错误:
React.createElement: type is invalid -- expected a string (for built-in components) or a class/function (for composite components) but got: undefined. You likely forgot to export your component from the file it's defined in, or you might have mixed up default and named imports
我正在尝试将样式添加到带有样式组件的活动链接中。
我有一个导航栏,根据哪个链接当前是活动的,相应的链接将有一个样式添加到其中。
谢谢
import React from 'react'
import Link from 'next/link'
import { useRouter } from 'next/router'
import { bool } from 'prop-types';
import StyledSidebar from '../../styles/header/styled.sidebar'
React文档说:React is pretty flexible but it has a single strict rule: all React components must act like pure functions with respect to their props.
为什么会这样呢?
我猜如果你直接改变属性的值,组件不会重新渲染,这就是我们必须使用setState的原因。但我仍然不明白这背后的原因。为什么组件就其道具而言必须类似于纯函数?
我在尝试隐藏页眉、页脚和登录页面时遇到了以下问题
这是我的密码:
import React, { Component } from 'react';
import Header from './components/Header';
import Footer from './components/Footer';
import { BrowserRouter as Router, Route } from 'react-router-dom';
import Routes from './routes';
我的项目使用dvajs(基于redux和redux-saga),下面的代码是在单击按钮后发送请求,通过连接更改状态,然后调用ant design组件message.error amessage.success(类似于警告)来提醒您。
import type { Dispatch } from 'umi';
import ProForm, { ProFormText } from '@ant-design/pro-form';
import { message } from 'antd';
const tip = (type: string, c