React组件传参方式你了解吗

// ParentComponent.js
import React, { useState } from 'react';
import ChildComponent from './ChildComponent';
​
function ParentComponent() {
  const [messageFromChild, setMessageFromChild] = useState('');
​
  const handleMessageFromChild = (message) => {
    setMessageFromChild(message);
  };
​
  return (
    <div>
      <h1>Parent Component</h1>
      <p>Message from Child: {messageFromChild}</p>
      <ChildComponent giveChildren={parentData} onMessage={handleMessageFromChild} />
    </div>
  );
}
​
export default ParentComponent;

// ChildComponent.js
​
//1.函数式组件
​
import React from 'react';
​
function ChildComponent(props) {
  const { onMessage , parentData } = props;
  const sendMessageToParent = () => {
    onMessage('Hello from Child!');
  };
​
  return (
    <div>
      <h2>Child Component</h2>
      <h2>{ parentData }</h2>
      <button onClick={sendMessageToParent}>Send Message to Parent</button>
    </div>
  );
}
​
export default ChildComponent;
​
//1. 类组件
​
import React, { Component } from 'react'
​
export default class ChildComponent extends Component {
    render() {
        return (
            <div>
                {this.props.parentToChild}
            </div>
        )
    }
}

//跨组件通信
import React, { Component } from 'react'
//创建context 给初始值
const UserMessage = React.createContext({
    nickName: 'yyy',
    level: 1
})
​
export default class TextSingal extends Component {
    constructor(props) {
        super(props)
        this.state = {
            nickName: 'kkk',
            level: 99,
            name: 'ppp',
            age: 9999
        }
    }
    render() {
        const { name, age } = this.state
        return (
            <div>
                <h2>爷爷组件</h2>
                <h3>name:{name}</h3>
                <h3>age:{age}</h3>
                {/* 改变数据孙组件也更新 */}
                <button onClick={() => this.handelClick()}>updated</button>
                {/* 传入state对象和foo回调函数 */}
                {/* foo函数用于孙组件和爷组件通信 */}
                <UserMessage.Provider value={{ ...this.state, foo: (name, age) => this.updateDatas(name, age) }}>
                    <Father />
                </UserMessage.Provider>
​
            </div>
        )
    }
    handelClick() {
        this.setState({
            nickName: '虎威神',
            level: 9999
        })
    }
    updateDatas(name, age) {
        this.setState({
            name,
            age
        })
    }
}
​
class Father extends Component {
    render() {
        return (
            <div>
                <h2>爸爸组件</h2>
                <Son />
            </div>
        )
    }
}
class Son extends Component {
    render() {
        // 解构
        const { nickName, level, foo } = this.context
        return (
            <div>
                <h2>儿子组件</h2>
                <h3>nickname:{nickName}</h3>
                <h3>level:{level}</h3>
                {/* 下面两种调用方式都可以 */}
                {/* 改变爷组件的数据 */}
                <button onClick={() => this.handelClick()}>updated</button>
                <button onClick={() => foo('牛霸天', 18)}>updated</button>
            </div>
        )
    }
    handelClick() {
        this.context.foo('牛霸天', 18)
    }
}
// 接受爷组件传递的值
Son.contextType = UserMessage

//父组件
import React, {Component} from "react"
import Abrother from './Abrother'
import Bbrother from './Bbrother'
​
export default class common extends Component {
    // 公共的组件部分
    state = {
        inputValue:''
    }
​
    handleUpdate = (inputValue) => {
        this.setState({
            inputValue
        })
    }
​
    render(){
        return(
            <>
              <Abrother sendFn={this.handleUpdate}/>
              <Bbrother sendValue={this.state.inputValue}/>
            </>
        )
    }
}

import React,{Component} from "react";
​
export default class Abrother extends Component {
​
    // 兄弟组件A需要将值先传给一个公共的父组件
    state = {
        inputValue:''
    }
​
    handleChange = (e)=>{
        console.log(e.target.value);
        this.setState({
            inputValue:e.target.value
        })
    }
    handleSend = () => {
        const {sendFn} = this.props;
        sendFn(this.state.inputValue)
    }
​
    render(){
        return(
            <>
               <div>
                   <span>A组件</span>
                   <input type='text' value={this.state.inputValue} onChange={this.handleChange}></input>
                   <button onClick={this.handleSend}>发送A组件的值</button>
               </div>
            </>
        )
    }
}

import React, {Component} from "react"
​
export default class Bbrother  extends Component {
​
​
    render(){
        const { sendValue} = this.props;
        return (
            <div>
                <span>b组件</span>
                <h1>{ sendValue }</h1>
            </div>
        )
    }
}