[JavaScript知识库]react组件传递

// 父传子组件

import React from 'react';
import ReactDOM from 'react-dom';

class Father extends React.Component{
    state = {
        message:"刘德华bb",
    }
    render() {
        return(
            <div>
                父组件|调用子组件：<Child msg={this.state.message}/>
            </div>
        )
    }
}

// function Child(props){
//     return <div>{props.name}</div>
// }
const Child = (props)=>{
    return <div>子组件内容 {props.msg} </div>
}

ReactDOM.render(<Father/>,document.getElementById("root"))

//子传父 利用回调函数 父组件提供回调函数 将要传递的数据作为回调函数参数
//1.父组件提供一个函数 接收参数
//2.将该函数作为属性的值 传递给子组件
//3.子组件通过props调用回调函数
//4.将子组件的数据作为参数传递给回调函数

import React from 'react';
import ReactDOM from 'react-dom';


class Father extends React.Component{
    state ={
        m:"",
    }
    getChildMsg = (msg)=>{
        console.log("接收来自子组件的东西",msg)
        this.setState({
            m:msg,
        })
    }
    render() {
        return(
            <div>
                <Child  get={this.getChildMsg} />
                {this.state.m}
            </div>
        )
    }
}

class Child extends React.Component {

    state ={
        msg:"子组件数据斗鱼",
    }
    handleClick = ()=> {
       // this.state.msg作为回调函数的参数  传到父组件
      this.props.get(this.state.msg)
    }

    render() {
        return (
            <button onClick={this.handleClick}> 点击：给父组件传东西</button>
        )

    }
}
ReactDOM.render(<Father/>,document.getElementById("root"))

// ——————————————————————兄弟组件通讯

import React from "react";
import ReactDOM from 'react-dom';

class Father extends React.Component{
    state = {
        number:1,
    }

    handClick = ()=>{
        this.setState({
            number:this.state.number+1,
        })
    }
    render(){
        return(
            <div>点击次数：
                <Child1 number={this.state.number}/>
                <Child2 handClick={this.handClick}/>
            </div>

        )
    }
}

const Child1 = (props) =>{
    return <div>{props.number}</div>
}


const Child2 = (props) =>{
    return <button onClick={()=>{props.handClick()}}>点击</button>
}

ReactDOM.render(<Father/>,document.getElementById("root"))