React学习笔记2017-12-31

Z时代
2024-01-10
分类：综合

react

课程：https://coding.imooc.com/class/chapter/150.html

第一章：介绍

第二章：知识储备

React开发环境

1.安装Nodejs

2.安装Visual Studio Code

安装create-react-app全局库，这是官方开发的一个react脚手架工具

npm install -g create-react-app

创建第一个react应用程序

#create-react-app创建一个示例项目

create-react-app react-demo

经过一段时间的等待，项目已经生成了

运行项目

cd react-demo

npm start

命令应该会自动打开浏览器，并打开http://localhost:3000

安装redux

npm install redux --save

弹出所有配置文件，将所有的配置文件显示出来，这个过程是不可逆的，会安装另外一些依赖

npm run eject #弹出自定义配置

第三章：react基础知识回顾

关于事件调用方法时，this的问题，解决方法有三个：

1：在constructor()构造方法中加入代码

class Yiying extends Component {
  constructor(props) {
    super(props);
    this.state = {
      solder: ['虎子', '柱子', '王根生']
    }
    //在构造函数加入bind
    this.addSolder = this.addSolder.bind(this);
  }
  addSolder() {
    this.setState({
      solder: [...this.state.solder, '新兵' + Math.random()]
    });
  }
  render() {
    return <div>
      一营营长，{this.props.leader}
      <button onClick={this.addSolder}>新兵入伍</button>
      <ul>
        {this.state.solder.map(v => {
          return <li key={v}>{v}</li>
        })}
      </ul>
    </div>
  }
}

View Code

2：在rander方法中，使用箭头函数调用方法

class Yiying extends Component {
  constructor(props) {
    super(props);
    this.state = {
      solder: ['虎子', '柱子', '王根生']
    }
  }
  addSolder() {
    this.setState({
      solder: [...this.state.solder, '新兵' + Math.random()]
    });
  }
  render() {
    return <div>
      一营营长，{this.props.leader}
      {/*在调用方法时加入箭头函数*/}
      <button onClick={() => this.addSolder()}>新兵入伍</button>
      <ul>
        {this.state.solder.map(v => {
          return <li key={v}>{v}</li>
        })}
      </ul>
    </div>
  }
}

View Code

3：将方法函数修改为箭头函数

class Yiying extends Component {
  constructor(props) {
    super(props);
    this.state = {
      solder: ['虎子', '柱子', '王根生']
    }
  }
  //修改方法为箭头函数
  addSolder = () => {
    this.setState({
      solder: [...this.state.solder, '新兵' + Math.random()]
    });
  }
  render() {
    return <div>
      一营营长，{this.props.leader}
      <button onClick={this.addSolder}>新兵入伍</button>
      <ul>
        {this.state.solder.map(v => {
          return <li key={v}>{v}</li>
        })}
      </ul>
    </div>
  }
}

View Code

react生命周期

class App extends Component {  
  componentWillMount() {
    console.log('====================================');
    console.log('将要加载');
    console.log('====================================');
  }
  componentDidMount() {
    console.log('====================================');
    console.log('已经加载');
    console.log('====================================');
  }
  render() {
    const boss = '李云龙';
    console.log('====================================');
    console.log('正在加载');
    console.log('====================================');
    return (
      <div>
        独立团，团长{boss}
        <Yiying leader='张大喵'></Yiying>
        <Qibinglian leader='孙德胜'></Qibinglian>
      </div>
    );
  }
}

View Code

在react的组件，如果是普通的组件，则会继承至react.Component

class Yiying extends Component {
  constructor(props) {
    super(props);
    this.state = {
      solder: ['虎子', '柱子', '王根生']
    }
  }
  //修改方法为箭头函数
  addSolder = () => {
    this.setState({
      solder: [...this.state.solder, '新兵' + Math.random()]
    });
  }
  render() {
    return <div>
      一营营长，{this.props.leader}
      <Button onClick={this.addSolder} type='primary'>新兵入伍</Button>
      <List renderHeader={() => '士兵列表'}>
        {this.state.solder.map(v => {
          return <Item key={v}>{v}</Item>
        })}
      </List>
    </div>
  }
}

View Code

如果该组件只有rander方法，不需要其他任何的事件等，可以使用以下写法，也是可以的

function Qibinglian(props) {
  return <div>骑兵连连长{props.leader}</div>
}

调用时，直接使用同样的方式

class App extends Component {
  render() {
    const boss = '李云龙';
    return (
      <div>
        独立团，团长{boss}
        <Yiying leader='张大喵'></Yiying>
        <Qibinglian leader='孙德胜'></Qibinglian>//该组件只显示，不做其他事件等响应
      </div>
    );
  }
}

antd-mobile引用

npm install antd-mobile --save

//引用组件
import {Button} from 'antd-mobile';
//引用样式
import 'antd-mobile/dist/antd-mobile.css';
//组件
<Button onClick={this.addSolder} type='primary'>新兵入伍</Button>

如果想按需加载antd-mobile样式，可以在运行过npm run ejest后，安装一个插件

npm install babel-plugin-import --save-dev

生成的package.json中找到babel节点，修改为下内容

  "babel": {
    "presets": [
      "react-app"
    ],
    "plugins":[
      ["import", { "libraryName": "antd-mobile", "style": "css" }]
    ]
  },

这时，react组件中，就不再需要引用antd-mobile的css了

代码是为以下

import React, { Component } from 'react';
import { Button, List } from 'antd-mobile';
const Item = List.Item;
class App extends Component {
  render() {
    const boss = '李云龙';
    return (
      <div>
        独立团，团长{boss}
        <Yiying leader='张大喵'></Yiying>
        <Qibinglian leader='孙德胜'></Qibinglian>
      </div>
    );
  }
}
function Qibinglian(props) {
  return <div>骑兵连连长{props.leader}</div>
}
class Yiying extends Component {
  constructor(props) {
    super(props);
    this.state = {
      solder: ['虎子', '柱子', '王根生']
    }
  }
  //修改方法为箭头函数
  addSolder = () => {
    this.setState({
      solder: [...this.state.solder, '新兵' + Math.random()]
    });
  }
  render() {
    return <div>
      一营营长，{this.props.leader}
      <Button onClick={this.addSolder} type='primary'>新兵入伍</Button>
      <List renderHeader={() => '士兵列表'}>
        {this.state.solder.map(v => {
          return <Item key={v}>{v}</Item>
        })}
      </List>
    </div>
  }
}
export default App;

App.js

{
  "name": "react-demo",
  "version": "0.1.0",
  "private": true,
  "dependencies": {
    "antd-mobile": "^2.1.3",
    "autoprefixer": "7.1.6",
    "babel-core": "6.26.0",
    "babel-eslint": "7.2.3",
    "babel-jest": "20.0.3",
    "babel-loader": "7.1.2",
    "babel-preset-react-app": "^3.1.0",
    "babel-runtime": "6.26.0",
    "case-sensitive-paths-webpack-plugin": "2.1.1",
    "chalk": "1.1.3",
    "css-loader": "0.28.7",
    "dotenv": "4.0.0",
    "eslint": "4.10.0",
    "eslint-config-react-app": "^2.0.1",
    "eslint-loader": "1.9.0",
    "eslint-plugin-flowtype": "2.39.1",
    "eslint-plugin-import": "2.8.0",
    "eslint-plugin-jsx-a11y": "5.1.1",
    "eslint-plugin-react": "7.4.0",
    "extract-text-webpack-plugin": "3.0.2",
    "file-loader": "1.1.5",
    "fs-extra": "3.0.1",
    "html-webpack-plugin": "2.29.0",
    "jest": "20.0.4",
    "object-assign": "4.1.1",
    "postcss-flexbugs-fixes": "3.2.0",
    "postcss-loader": "2.0.8",
    "promise": "8.0.1",
    "raf": "3.4.0",
    "react": "^16.2.0",
    "react-dev-utils": "^4.2.1",
    "react-dom": "^16.2.0",
    "redux": "^3.7.2",
    "style-loader": "0.19.0",
    "sw-precache-webpack-plugin": "0.11.4",
    "url-loader": "0.6.2",
    "webpack": "3.8.1",
    "webpack-dev-server": "2.9.4",
    "webpack-manifest-plugin": "1.3.2",
    "whatwg-fetch": "2.0.3"
  },
  "scripts": {
    "start": "node scripts/start.js",
    "build": "node scripts/build.js",
    "test": "node scripts/test.js --env=jsdom"
  },
  "jest": {
    "collectCoverageFrom": [
      "src/**/*.{js,jsx,mjs}"
    ],
    "setupFiles": [
      "<rootDir>/config/polyfills.js"
    ],
    "testMatch": [
      "<rootDir>/src/**/__tests__/**/*.{js,jsx,mjs}",
      "<rootDir>/src/**/?(*.)(spec|test).{js,jsx,mjs}"
    ],
    "testEnvironment": "node",
    "testURL": "http://localhost",
    "transform": {
      "^.+\\.(js|jsx|mjs)$": "<rootDir>/node_modules/babel-jest",
      "^.+\\.css$": "<rootDir>/config/jest/cssTransform.js",
      "^(?!.*\\.(js|jsx|mjs|css|json)$)": "<rootDir>/config/jest/fileTransform.js"
    },
    "transformIgnorePatterns": [
      "[/\\\\]node_modules[/\\\\].+\\.(js|jsx|mjs)$"
    ],
    "moduleNameMapper": {
      "^react-native$": "react-native-web"
    },
    "moduleFileExtensions": [
      "web.js",
      "mjs",
      "js",
      "json",
      "web.jsx",
      "jsx",
      "node"
    ]
  },
  "babel": {
    "presets": [
      "react-app"
    ],
    "plugins": [
      [
        "import",
        {
          "libraryName": "antd-mobile",
          "style": "css"
        }
      ]
    ]
  },
  "eslintConfig": {
    "extends": "react-app"
  },
  "devDependencies": {
    "babel-plugin-import": "^1.6.3"
  }
}