基于WebStorm的react实现todolist记事本基础功能

一.自动化生成react基本框架

创建react脚手架项目 直接用  npx  create-react-app aa（aa为自己的项目名称）  命令

等待软件下载好基础包后,输入cd aa(转到所创项目名) 命令,npm start 命令启动服务,可以看见自动生成跳转到一个react展示页面

二.更改App.js等内容实现功能

App.js文件

import Header from "./header/header";
import List from "./list/list";
import Footer from "./footer/footer";
import React from "react";

export default class App extends React.***ponent{
    //初始化状态
    state ={todos: [
            {id:'001',name:'吃饭',done:true},
            {id:'002',name:'睡觉',done:false},
            {id:'003',name:'打代码',done:true},
        ]}

    //addTodo用于添加一个todo，接收的参数是todo对象
    addTodo=(todoObj)=>{
        //获取原todos
        const {todos}=this.state
        //追加一个todos
        const newTodos=[todoObj,...todos]
        //更新状态
        this.setState({todos: newTodos})
    }

    //用于更新一个todo对象
    updateTodo=(id,done)=>{
        // 获取状态中的todos
        const {todos}=this.state
        //匹配处理数据
        const newTodos=todos.map((todoObj)=>{
            if (todoObj.id ===id)return{...todoObj,done:done}
            else return todoObj
        })
        this.setState({todos:newTodos})
    }

    //用于删除一个todo对象
    deleteTodo=(id)=>{
        //获取原来的todos
        const {todos}=this.state
        //删除指定id的todo对象
        const newTodos=todos.filter((todoObj)=>{
            return todoObj.id!==id
        })
        //更新状态
        this.setState({todos: newTodos})
    }

    //用于全选
    checkAllTodo=(done)=>{
        //获取原来的todos
        const {todos}=this.state
        //加工数据
        const newTodos=todos.map((todoObj)=>{
            return{...todoObj,done}
        })
        //更新状态
        this.setState({todos: newTodos})
    }

    //清除所用已完成的任务
    clearAllDone = ()=>{
        //获取原来的todos
        const {todos}=this.state
        //过滤数据
        const newTodos=todos.filter((todoObj)=>{
            return todoObj.done === false
        })
        this.setState({todos: newTodos})
    }
    render() {
        const {todos}=this.state
        return (
            <div className="todo-container">
                <div className="todo-wrap">
                    <Header addTodo={this.addTodo}/>
                    <List todos={todos} updateTodo={this.updateTodo} deleteTodo={this.deleteTodo}/>
                    {<Footer todos={todos} checkAllTodo={this.checkAllTodo} clearAllDone={this.clearAllDone}/>}
                </div>

            </div>
        );
    }
}

Header.js文件

import React from "react";
import PropTypes from "prop-types";
import {nanoid} from "nanoid";

export default class Header extends React.***ponent {
    //对接收的props进行：类型、必要性的限制
    static propTypes={
        addTodo:PropTypes.func.isRequired
    }
    //键盘事件的回调函数
    handleKeyUp=(event)=>{
        //解构发展获取keyCode,target
        const {keyCode,target}=event
        //判断是否是回车按键
        if(keyCode !==13)return
        //添加的todo名字不能为空
        if (target.value.trim()===''){
            alert('输入不能为空')
            return
        }
        //准备好一个todo对象
        const todoObj={id:nanoid,name:target.value,done:false}
        //将todoObj传递给App
        this.props.addTodo(todoObj)
        //清空输入
        target.value=''
    }
    render() {
        return (
            <div className="todo-header">
                <input onKeyUp={this.handleKeyUp} type="text" placeholder="请输入你的任务名称，按回车键确认"/>
            </div>
        );
    }
}

List.js文件

import React from "react";
import Item from "../item/item";
import PropTypes from "prop-types";

export default class List extends React.***ponent {
    //对接收的props进行：类型、必要性的限制
    static propTypes={
        todos:PropTypes.array.isRequired,
        updateTodo:PropTypes.func.isRequired,
        deleteTodo:PropTypes.func.isRequired
    }
    render() {
        const {todos,updateTodo,deleteTodo} = this.props
        return (
            <ul className="todo-main">
                {
                    todos.map((todo)=>{
                        return  <Item key={todo.id} {...todo}  updateTodo={updateTodo} deleteTodo={deleteTodo}/>
                    })

                }

            </ul>
        );
    }
}

Item.js文件

import React from "react";
import "./Item.css"
export default class Item extends React.***ponent {
    //标识鼠标移入、移出
    state={mouse:false}
    //勾选或取消勾选某一个toso的回调函数
    handleCheck=(id)=>{
        return(event)=>{
            this.props.updateTodo(id,event.target.checked)
        }
    }
    //删除某一个toso的回调函数
    handleDelete=(id)=>{
        if (window.confirm('确定删除吗？')){
            this.props.deleteTodo(id)
        }
    }
    //鼠标移入、移出的回调函数
    handleMouse =(flag)=>{
        return()=>{
            this.setState({mouse:flag})
        }
    }
    render() {
        const {id,name,done}=this.props
        const {mouse}=this.state
        return (
            <li style={{backgroundColor:mouse?'#ddd':'white'}} onMouseLeave={this.handleMouse(false)} onMouseEnter={this.handleMouse(true)}>
                <label>
                    <input type="checkbox" checked={done} onChange={this.handleCheck(id)}/>
                    <span>{name}</span>
                </label>
                <button
                    onClick={()=>this.handleDelete(id)}
                    className="btn btn-danger"
                    style={{display: mouse?"block":"none"
                    }}>删除</button>
            </li>
        );
    }
}

 Footer.js文件

import React from "react";

export default class Fooder extends React.***ponent {
    //全选checkcbox的回调
    handleCheckAll=(event)=>{
        this.props.checkAllTodo(event.target.checked)
    }
    //清除所用已完成的任务
    handleClearAllDone =()=>{
        this.props.clearAllDone()
    }
    render() {
        const {todos}=this.props
        //已完成的个数
        const doneCount=todos.reduce((pre,current)=>{return pre+(current.done?1:0)},0)

        //总数
        const total =todos.length
        return (
            <div className="todo-footer">
                <label>
                    <input type="checkbox" onChange={this.handleCheckAll}
                           checked={doneCount === total&&total!==0 ? true:false}/>
                </label>
                <span>
                <span>已完成{doneCount}</span>/全部{total}
            </span>
                <button onClick={this.handleClearAllDone} className="btn btn-danger">清除已完成任务</button>
            </div>
        );
    }
}

最终实现效果如下图所示:

如果想改变样式,需引入css文件,对布局进行进一步处理

了解详细原理请参考以下链接

【尚硅谷React教程（已加更新版内容，B站最火）】 https://www.bilibili.***/video/BV1wy4y1D7JT/?p=56&share_source=copy_web&vd_source=db9c6d25ddec3a6c8b592f58d4d29cd9