访问ReactJS中另一个组件的状态？

class ParentComponent extends React.Component {
  constructor(props) {
    super(props);
    this.state = {
      count: 0
    };
  }

  render() {
    return (
      <ChildComponent count={this.state.count} />
    );
  }
}

class ChildComponent extends React.Component {
  render() {
    return (
      <div>{this.props.count}</div>
    );
  }
}

class ParentComponent extends React.Component {
  constructor(props) {
    super(props);
    this.state = {
      count: 0
    };
    this.updateCount = this.updateCount.bind(this);
  }

  updateCount(newCount) {
    this.setState({ count: newCount });
  }

  render() {
    return (
      <ChildComponent updateCount={this.updateCount} />
    );
  }
}

class ChildComponent extends React.Component {
  handleClick() {
    this.props.updateCount(10); // 调用父组件的回调函数更新状态
  }

  render() {
    return (
      <button onClick={this.handleClick.bind(this)}>Update Count</button>
    );
  }
}