父子组件通讯

• 父组件将方法传递给子组件，在 React 当中也会将父组件传递的，数据和函数信息直接存放在子组件当中，的 Props 属性对象当中
• React 的父子组件通讯的实现其实就是利用，函数的互相调用进行实现完成的

Header.js:

import React from 'react';
import './Header.css';
import ReactTypes from "prop-types";

class Header extends React.Component {
    constructor(props) {
        super(props);
    }

    render() {
        return (
            <div>
                <div className={'header'}>我是头部</div>
                <button onClick={() => {
                    this.btnClickFn()
                }}>我是按钮
                </button>
            </div>
        )
    }

    static defaultProps = {
        name: '小灰灰',
        age: 18
    }

    static propTypes = {
        name: ReactTypes.string,
        age: ReactTypes.number
    }

    btnClickFn() {
        this.props.fatherFn('BNTang', 18);
    }
}

export default Header;

App.js:

import React from 'react';
import './App.css';
import Footer from "./components/Footer";
import Main from "./components/Main";
import Header from "./components/Header";

class App extends React.Component {
    render() {
        return (
            <div>
                <Header name={'BNTang'} age={18} fatherFn={this.fatherFunction.bind(this)}/>
                <Main/>
                <Footer/>
            </div>
        )
    }

    fatherFunction(name, age) {
        console.log(name, age);
    }
}

export default App;