react+react-beautiful-dnd实现代办事项思路详解

import React from 'react'
import ReactDOM from 'react-dom'
import App from './App'
import 'bulma-start/CSS/main.css' // 引入bulma样式
ReactDOM.render(
  <App/>,
  document.getElementById('root')
)

return(
<Provider value={{
	'要在tree传递的名字':this.'具体属性或方法'
}}>
自己的代码
</Provider>
)

import React,{ Component} from "react";
import TodoHeader from './components/TodoHeader.jsx'
import TodoInput from "./components/TodoInput";
import TodoList from "./components/TodoList";
import TodoFoot from "./components/TodoFoot";
import {Provider} from "./untils/with-context" // 引入TodoContext组件
export default class App extends Component{
    state ={
        todos:Array(6).fill(null).map((_,index)=>({
            id:index++,
            title:'待办事项'+index++,
            completed: Math.random()>0.5,
        }))
    }
    // 拖拽后的更新state处理函数
    drag(newTodos){
        this.setState({
            todos:[...newTodos],
        })

    }
    // 添加事件处理函数
    addTodoItem=title=>{
        this.setState({
            todos:[
                ...this.state.todos,
                {
                    
                    id:Math.random(),
                    title,
                    completed:false,
                }
            ]
        })

    }
    // 删除事件处理函数
    delTodo=id=>{
        this.setState({
            todos:this.state.todos.filter(todo=>todo.id !==id)
        })
    }
    // 更改事件状态处理函数
    chanGComple=id=>{
        this.setState({
            todos:this.state.todos.map(todo=>{
                if(todo.id === id){
                    todo.completed=!todo.completed
                }
                return todo
            })
        })

    }
    // 根据总选框状态设置每个单选框状态
    allCheckbox=(status)=>{
        this.setState({
            todos:this.state.todos.map(todo=>{
                todo.completed=status
                return todo
            })
        })
    }
    // 删除已完成事件
    delCompelted=()=>{
        this.setState({
            todos:this.state.todos.filter(todo=>!todo.completed)
        })
    }
    render() {
        return(
            <Provider value={{
                todos:this.state.todos,
                changComple:this.changComple,
                delTodo:this.delTodo,
                allCheckbox:this.allCheckbox,
                delCompelted:this.delCompelted,
            }}>
                <article className="panel is-success">
                    <TodoHeader/>
                    <TodoInput add={this.addTodoItem}/>
                    <TodoList todos={this.state.todos} drag={this.drag.bind(this)}/>
                    <TodoFoot/>

                </article>
            </Provider>

        )
    }
}

import {createContext} from "react";
// 创建creatContext对象
const TodoContext = createContext()
// 结构要用到的React组件
const {
    Provider, // 生产组件
    Consumer, // 消费组件
} = TodoContext
export {
    Provider,
    Consumer,
    TodoContext,
}

import React, { Component } from 'react'
export default class TodoHeader extends Component {
    render() {
        return (
            <p className="panel-heading">
                待办事项列表
            </p>
        )
    }
}

import React, {Component, createRef} from "react";
export default class TodoInput extends Component{
    state={
        inputValue:'输入代办事件', // 定义input输入框内容
    }
    inputRef=createRef() // 定义ref绑定DOM元素，作用是为下面自动获取焦点做准备
    // 输入框中输入的内容设置给state作用1：输入框内容改变2：后面提交添加事件拿到input内容
    handleChang=Event=>{
        this.setState({
            inputValue:Event.target.value
        })
    }
    // 添加代办事件
    handleDown=Event=>{
        // 验证下是否为空
        if(this.state.inputValue==='' || this.state.inputValue===null) return
        if(Event.keyCode ===13){
            this.add()
        }
    }
    // 添加处理函数
    add=()=>{
        // add方法通过props从App传入
        this.props.add(this.state.inputValue)
        this.state.inputValue=''
        // ref绑定后通过inputRef.current拿到DOM元素
        this.inputRef.current.focus()
    }
    render() {
        return(
                <div className="panel-block">
                    <p className="control has-icons-left">
                        <input
                            className="input is-success"
                            type="text"
                            placeholder="输入代办事项"
                            value={this.state.inputValue}
                            onChange={this.handleChang}
                            onKeyDown={this.handleDown.bind(this)} //该变this指向
                            ref={this.inputRef}
                        />
                    </p>
                </div>
        )
    }
}

<DragDropContext onDragEnd={this.onDragEnd}>
	<Droppable droppableId='columns'>
		{provided=>(
		<*
			 ref={provided.innerRef}
             {...provided.droppableProps}
             // 官方固定格式
		>
		自己的代码
		<*/>
		{provided.placeholder}
		)}
	</Droppable>
</DragDropContext>

<Draggable draggableId={String(id)} index={this.props.index}>
{provided=>(
	<*
	 {...provided.draggableProps}
     {...provided.dragHandleProps}
     ref={provided.innerRef}
	>
	自己的代码
	<*/>
	{provided.placeholder}
)}
</Draggable>

{draggableId: '5', type: 'DEFAULT', source: {…}, reason: 'DROP', mode: 'FLUID', …}
combine: null
destination: {droppableId: 'columns', index: 4} // 移动到第4个事件
draggableId: "5"
mode: "FLUID"
reason: "DROP"
source: {index: 5, droppableId: 'columns'} // 移动的第5个事件
type: "DEFAULT"
[[Prototype]]: Object

import React,{Component} from "react";
import TodoItem from "./TodoItem";
import PropTypes from 'prop-types'
import {DragDropContext} from 'react-beautiful-dnd'
import {Droppable} from 'react-beautiful-dnd'
export default class TodoList extends Component{
    // 类型检查
    static propTypes={
        todos:PropTypes.array.isRequired,
    }
    // 默认值
    static defaultProps = {
        todos: [],
    }
    // 根据choice数值决定渲染事项
    state={
        choice:1
    }
    // react-beautiful-dnd核心处理函数，负责交换后的处理（可以自定义）
    onDragEnd=result=>{
        console.log(result)
        const {destination,source,draggableId}=result
        if(!destination){ // 移动到了视图之外
            return
        }
        if( // 移动到原来位置，也就是位置不变
            destination.droppableId===source.droppableId &&
            destination.index===source.index
        ){ return;}
        const newTaskIds=Array.from(this.props.todos) // 转化为真正的数组
        newTaskIds.splice(source.index,1) // 删除移动的数组
        newTaskIds.splice(destination.index,0,this.props.todos[source.index]) // 在移动到的位置初放置被删除的数组
        // 调用App文件中的drag执行交换后的更改
        this.props.drag(newTaskIds)
    }
    // 点击时渲染不同DOM
    choice=(num)=>{
        this.setState({
            choice:num
        })
    }
    render() {
        let uls=null
        if(this.state.choice===1){
            uls=(<DragDropContext onDragEnd={this.onDragEnd}>
                    <Droppable droppableId='columns'>
                        {provided=>(
                            <ul
                                ref={provided.innerRef}
                                {...provided.droppableProps}
                            >
                                {this.props.todos.length>0
                                    ? this.props.todos.map((todo,index)=>{
                                        return (
                                            <TodoItem key={todo.id} todo={todo} index={index}/>
                                        )
                                    })
                                    :<div>添加代办事项</div>
                                }
                                {provided.placeholder}
                            </ul>
                        )}
                    </Droppable>
                </DragDropContext>)
        }else if(this.state.choice===2){
            // 过滤下事件
            let newtodos=this.props.todos.filter(todo=> todo.completed)
                uls=(<DragDropContext onDragEnd={this.onDragEnd}>
                    <Droppable droppableId='columns'>
                        {provided=>(
                            <ul
                                ref={provided.innerRef}
                                {...provided.droppableProps}
                            >
                                {newtodos.length>0
                                    ? newtodos.map((todo,index)=>{
                                        return (
                                            <TodoItem key={todo.id} todo={todo} index={index}/>
                                        )
                                    })
                                    :<div>暂无已完成事件</div>
                                }
                                {provided.placeholder}
                            </ul>
                        )}
                    </Droppable>
                </DragDropContext>)
        }else if(this.state.choice===3){
            // 过滤下事件
            let newtodos=this.props.todos.filter(todo=> !todo.completed)
            uls=(<DragDropContext onDragEnd={this.onDragEnd}>
                <Droppable droppableId='columns'>
                    {provided=>(
                        <ul
                            ref={provided.innerRef}
                            {...provided.droppableProps}
                        >
                            {newtodos.length>0
                                ? newtodos.map((todo,index)=>{
                                    return (
                                        <TodoItem key={todo.id} todo={todo} index={index}/>
                                    )
                                })
                                :<div>暂无未完成事件</div>
                            }
                            {provided.placeholder}
                        </ul>
                    )}
                </Droppable>
            </DragDropContext>)
        }
        return(
            <>
                   <p className="panel-tabs">
                         <a className="is-active" onClick={()=>this.choice(1)}>所有</a>
                         <a onClick={()=>this.choice(2)}>已完成</a>
                         <a onClick={()=>this.choice(3)}>未完成</a>
                    </p>
                  {uls}
            </>
        )
    }
}

return(
	 <Consumer>
	 {value=>{
	 const {结构要用的属性或方法的名字} = value
	 return(
	 	 自己的代码，value中含有Provider中传入的所有值
	 )
	 }}
	 </Consumer>
)

import React,{Component} from "react";
import {Consumer} from '../untils/with-context'
export default class TodoFoot extends Component{
    render() {
        return(
            <Consumer>
                {
                    value => {
                        const {allCheckbox,todos,delCompelted} = value
                        const completedNum =todos.filter(todo=>todo.completed).length
                        const AllChecked =todos.length?todos.every(todo=>todo.completed):false
                        return(
                            <div>
                                <label className="panel-block">
                                    <input type="checkbox" checked={AllChecked} onChange={(event)=>allCheckbox(event.target.checked)}/>全选
                                    <span>已完成{completedNum}</span>
                                    <span>一共{todos.length}</span>
                                </label>
                                <div className="panel-block">
                                    <button className="button is-success is-outlined is-fullwidth" onClick={delCompelted}>
                                        删除已完成
                                    </button>
                                </div>
                            </div>
                        )
                    }
                }
            </Consumer>

        )
    }
}

{
  "name": "react-demo",
  "version": "0.1.0",
  "private": true,
  "dependencies": {
    "@testing-library/jest-dom": "^5.11.4",
    "@testing-library/react": "^11.1.0",
    "@testing-library/user-event": "^12.1.10",
    "bulma-start": "^0.0.5",
    "react": "^17.0.2",
    "react-beautiful-dnd": "^13.1.0",
    "react-dom": "^17.0.2",
    "react-native": "^0.68.2",
    "react-scripts": "4.0.3",
    "redux-persist": "^6.0.0",
    "store": "^2.0.12",
    "WEB-vitals": "^1.0.1"
  },
  "scripts": {
    "start": "react-scripts start",
    "build": "react-scripts build",
    "test": "react-scripts test",
    "eject": "react-scripts eject"
  },
  "eslintConfig": {
    "extends": [
      "react-app",
      "react-app/jest"
    ]
  },
  "browserslist": {
    "production": [
      ">0.2%",
      "not dead",
      "not op_mini all"
    ],
    "development": [
      "last 1 chrome version",
      "last 1 firefox version",
      "last 1 safari version"
    ]
  }
}