hm-react-cli/template/app/src/components/Child.js

Create a Huimei React project by module

import { useEffect, Component } from 'react';

export default class Child extends Component {
    constructor(props) {
        super(props);
        this.Child2 = React.createRef();
    }

    componentDidMount() {
        this.Child2.current.innerHTML = '<div>123</div>';
    }

    componentDidUpdate() {
        // this.Child2.current.innerHTML = '<div>123</div>';
    }

    shouldComponentUpdate(nextProps, nextState) {
        // if (this.props.count !== nextProps.count) {
        //     return true;
        // }
    }

    render() {
        return (
            <>
                {/* <span>{count}</span> */}
                <div id="Child">
                    <span>span1</span>
                    <span id="Child2" ref={this.Child2}>
                        child2
                    </span>
                </div>
            </>
        );
    }
}