未在React中从子组件传递到父组件的值

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

function ParentComponent() {
  const [valueFromChild, setValueFromChild] = useState('');

  // 回调函数，用于接收子组件传递的值
  const handleValueFromChild = (value) => {
    setValueFromChild(value);
  };

  return (
    <div>
      <ChildComponent onValueChange={handleValueFromChild} />
      <p>从子组件传递的值：{valueFromChild}</p>
    </div>
  );
}

export default ParentComponent;

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

function ChildComponent(props) {
  const [inputValue, setInputValue] = useState('');

  // 处理输入框值变化
  const handleInputChange = (e) => {
    setInputValue(e.target.value);
  };

  // 将值通过回调函数传递给父组件
  const handleValuePassing = () => {
    props.onValueChange(inputValue);
  };

  return (
    <div>
      <input type="text" value={inputValue} onChange={handleInputChange} />
      <button onClick={handleValuePassing}>传递值给父组件</button>
    </div>
  );
}

export default ChildComponent;