React-在用户选择相同选项时选择onChange触发器

import React, { useState } from 'react';

const CitySelector = () => {
  const [selectedCity, setSelectedCity] = useState('');

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

  return (
    <div>
      <select value={selectedCity} onChange={handleChange}>
        <option value="">请选择城市</option>
        <option value="Beijing">北京</option>
        <option value="Shanghai">上海</option>
        <option value="Guangzhou">广州</option>
      </select>
      <p>你选择的城市是：{selectedCity}</p>
    </div>
  );
};

export default CitySelector;

const handleChange = (event) => {
  if (event.target.value !== selectedCity) {
    setSelectedCity(event.target.value);
  }
};