如何从子小部件调用setState *

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

  updateCount = () => {
    this.setState({ count: this.state.count + 1 });
  }

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

class ChildComponent extends React.Component {
  render() {
    return (
      <button onClick={this.props.updateCount}>Increase Count</button>
    );
  }
}