React.js: React下拉菜单不保存数据

import React, { useState } from 'react';

function DropdownMenu() {
  const [selectedValue, setSelectedValue] = useState('');

  const handleDropdownChange = (event) => {
    setSelectedValue(event.target.value);
  };

  return (
    <select value={selectedValue} onChange={handleDropdownChange}>
      <option value="option1">Option 1</option>
      <option value="option2">Option 2</option>
      <option value="option3">Option 3</option>
    </select>
  );
}

import React, { useRef } from 'react';

function DropdownMenu() {
  const dropdownRef = useRef(null);

  const handleButtonClick = () => {
    const selectedValue = dropdownRef.current.value;
    // 处理选中的值
  };

  return (
    <div>
      <select ref={dropdownRef}>
        <option value="option1">Option 1</option>
        <option value="option2">Option 2</option>
        <option value="option3">Option 3</option>
      </select>
      <button onClick={handleButtonClick}>保存</button>
    </div>
  );
}