单击按钮时，React setState不会自动填充数据

import React, { Component } from 'react';

class MyComponent extends Component {
  constructor(props) {
    super(props);
    this.state = {
      data: ''
    };
  }

  handleClick = () => {
    // 更新组件状态
    this.setState({ data: '新的数据' });
  }

  render() {
    return (
      <div>
        <button onClick={this.handleClick}>点击按钮</button>
        <p>{this.state.data}</p>
      </div>
    );
  }
}

export default MyComponent;