如何单击父组件中的按钮并访问子组件中的数据？

// 父组件
import React, { useState } from 'react';
import ChildComponent from './ChildComponent';

const ParentComponent = () => {
  const [childData, setChildData] = useState('');

  const handleClick = () => {
    // 访问子组件数据的逻辑
    console.log(childData);
  };

  return (
    <div>
      <ChildComponent onChildDataChange={setChildData} />
      <button onClick={handleClick}>点击按钮</button>
    </div>
  );
};

export default ParentComponent;

// 子组件
import React, { useState } from 'react';

const ChildComponent = ({ onChildDataChange }) => {
  const [childData, setChildData] = useState('');

  const handleChange = (event) => {
    setChildData(event.target.value);
    onChildDataChange(event.target.value);
  };

  return (
    <input type="text" value={childData} onChange={handleChange} />
  );
};

export default ChildComponent;