jsx

react-router：是react router的核心库 react-router-dom：是网页路由的解决方案，依赖于react-router react-router-native：是react-native解决移动端路由的解决方案，依赖于react-react 下面讲述的是react-router-dom的使用 这里用的react-router版本是5.x react-router5.x版本和react-router3.x使用上有很大不同 1安装路由模块 npm i –S react-router-dom 2路由的定义 App.jsx 这里定义了4个页面 <Router>定义一个路由实例，相当于一个路由容器 <Switch>标签让路由只能匹配单个<Route>，不具包含性的匹配多个路由 5.x的路由具有包含性和3.x的路由完全不同 exact属性让route进行严格匹配，只有路径完全一致才会匹配成功，默认值true，可以省略不写 eq： 在网页中匹配根路径’/’,路由匹配会按从上到下的顺序进行匹配，如果没有<Swith>标签，就会成功匹配’/’,’/about’,’/inbox’,’/coder’所有的<Route>标签，从而展示其相关的组件。 添加<Swith>标签后，路由只能匹配单个<Route>标签，因此这里只会匹配到path=’/’的<Route>标签

I'm having difficulty with some background images not loading. I've made some significant modifications to the initial create react app, my folder structure is now as follows: Note: I have omitted some files & folders, if you need more please let me know. App/ node_modules/ src/ client/ build/ node_modules/ public/ src/ css/ App.css images/ tree.png yeti.png App.jsx server/ package.json Procfile Here are the steps I take to create this issue: $ cd src/server && npm run dev This will boot up the dev server and open the browser to my app, everything is working fine except for some elements on

I have a little issue with React. I can't create a nested component with a for loop. What I want to do is create 9 cells of a table and then create 3 rows with 3 cells for every row and after that mount the 3 rows together and create a board 9x9. Let say that I want to get something like this, but using a loop class Board extends React.Component { renderSquare(i) { return <Square value={this.props.squares[i]} onClick={() => this.props.onClick(i)} />; } render(){ return( <div> <div className="board-row"> {this.renderSquare(0)} {this.renderSquare(1)} {this.renderSquare(2)} </div> <div className=

I'm wondering what's the best practice for accessing the DOM elements inside my render function from the same component. Note that I will be rendering this component multiple times on a page. e.g. var TodoItem = React.createClass({ ... render:function(){ function oneSecLater(){ setTimeout(function(){ //select the current className? this doesn't work, but it gives you an idea what I want. document.getElementsByClassName('name').style.backgroundColor = "red"; )}, 1000); } return( <div className='name'>{this.oneSecLater}</div> ) }) Here, no need to use setTimeout. There are lifecycle methods for

在写react代码的时候，大部分同学应该都是写JSX。因为相比于写纯JavaScript。写JSX为我们去写组件，比写一些在JavaScript当中写类似于html结构的这种代码是要方便非常非常多的，他的可阅读性，可维护性都要高很多的。那么JSX他的魔力在哪里，能够让我们在JS里面写html代码。 JSX相对于JavaScript来讲，他的唯一的一个区别就是他可以写类似于html的标签。 https://www.babeljs.cn/repl 在这个网址写示例 左边 <div></div> 右边 "use strict"; React.createElement("div", null); 在左边我们声明了html的标签，他在右边会返回一个我们在react当中我们需要返回的一个对象。这就是 JSX 到 JS 的一个转换过程 我们会发现通过这种标签写的，他最终都会转换成 React.createElement 。里面的标签名，属性，内容都会通过参数给他。 左边 <div id='div' key='key'>test</div> 右边 React.createElement("div", { id: "div", key: "key" }, "test"); 会把所有的属性放在第二个参数，第二个参数是个对象，都会加在这个对象里面给他。第三个参数在 React 中称为 children

i have a circle and a grradient to fill in it, i put in the gradient and call him in path by style fill. import React,{PropTyoes} from 'react'; import {connect} from 'react-redux'; import * as Actions from '../controllers/Actions'; export default class MyComp extends React.Component { constructor(props, context){ super(props, context); } render(){ return ( <svg xmlns="http://www.w3.org/2000/svg" xmlnsXlink="http://www.w3.org/1999/xlink" viewBox="0 0 983.4 983.4"> <g> <linearGradient id="linear-gradient" gradientUnits="userSpaceOnUse" x1="1041.6901" y1="169.485" x2="1383.9301" y2="169.485"