React获取组件实例的属性

class MyComponent extends React.Component {
  constructor(props) {
    super(props);
    this.myRef = null;
  }

  componentDidMount() {
    console.log(this.myRef.someProperty); // 访问组件实例的属性
  }

  render() {
    return <div ref={ref => this.myRef = ref}>Hello, World!</div>;
  }
}

class MyComponent extends React.Component {
  constructor(props) {
    super(props);
    this.myRef = React.createRef();
  }

  componentDidMount() {
    console.log(this.myRef.current.someProperty); // 访问组件实例的属性
  }

  render() {
    return <div ref={this.myRef}>Hello, World!</div>;
  }
}