在React中从Select元素获取多个值的策略与实践

const rates = [
  { id: 'r8f8hd8', service: 'Standard Shipping', amount: 45 },
  { id: 'r8f8hd', service: 'Express Shipping', amount: 450 },
  { id: 'r8f8hd9', service: 'Economy Shipping', amount: 20 },
];

import React, { useState } from 'react';

function ShippingRateSelector() {
  const rates = [
    { id: 'r8f8hd8', service: 'Standard Shipping', amount: 45 },
    { id: 'r8f8hd', service: 'Express Shipping', amount: 450 },
    { id: 'r8f8hd9', service: 'Economy Shipping', amount: 20 },
  ];

  const [selectedRate, setSelectedRate] = useState(null);

  const handleRateChange = (e) => {
    const selectedRateId = e.target.value;
    // 从原始数据数组中查找完整的费率对象
    const rateDetails = rates.find(rate => rate.id === selectedRateId);
    setSelectedRate(rateDetails);
    console.log('Selected Rate ID:', selectedRateId);
    console.log('Selected Rate Details:', rateDetails);
  };

  return (
    <div className="p-4">
      <label htmlFor="shipping-rate" className="block text-lg font-medium text-gray-700 mb-2">
        选择运费费率:
      </label>
      <select
        id="shipping-rate"
        onChange={handleRateChange}
        className="w-8/12 h-14 rounded p-2 border border-gray-300 focus:ring-blue-500 focus:border-blue-500"
        value={selectedRate ? selectedRate.id : ''} // 控制组件，绑定当前选中值
      >
        <option disabled value="">
          请选择一个运费费率
        </option>
        {rates.map((rate) => (
          <option value={rate.id} key={rate.id}>
            {rate.service} (${rate.amount})
          </option>
        ))}
      </select>

      {selectedRate && (
        <div className="mt-4 p-4 border rounded bg-gray-50">
          <h3 className="text-md font-semibold">当前选择的费率:</h3>
          <p>服务: {selectedRate.service}</p>
          <p>金额: ${selectedRate.amount}</p>
          <p>ID: {selectedRate.id}</p>
        </div>
      )}
    </div>
  );
}

export default ShippingRateSelector;

import React, { useState } from 'react';

function ShippingRateSelectorAlternative() {
  const rates = [
    { id: 'r8f8hd8', service: 'Standard Shipping', amount: 45 },
    { id: 'r8f8hd', service: 'Express Shipping', amount: 450 },
    { id: 'r8f8hd9', service: 'Economy Shipping', amount: 20 },
  ];

  const [selectedRateDetails, setSelectedRateDetails] = useState(null);

  const handleRateChange = (e) => {
    // e.target.value 此时是选项的索引（字符串形式）
    const selectedIndex = parseInt(e.target.value, 10);

    // 获取对应的DOM option元素
    // 注意：e.target.options 是一个HTMLCollection，通过索引访问
    // 还需要考虑第一个 disabled option 占用的索引
    const selectedOption = e.target.options[selectedIndex];

    if (selectedOption) {
      // 从原始 rates 数组中根据索引获取数据 (selectedIndex - 1 是因为第一个是 disabled option)
      const rateDetails = rates[selectedIndex - 1]; // 假设 rates 数组顺序与 option 对应

      setSelectedRateDetails(rateDetails);
      console.log('Selected Option DOM:', selectedOption);
      console.log('Selected Rate Details (from array):', rateDetails);
      // 如果需要，也可以尝试从DOM元素读取自定义属性，但这通常不推荐
      // const customId = selectedOption.getAttribute('data-id');
      // const customAmount = selectedOption.getAttribute('data-amount');
    }
  };

  return (
    <div className="p-4 mt-8">
      <label htmlFor="shipping-rate-alt" className="block text-lg font-medium text-gray-700 mb-2">
        选择运费费率 (替代方案):
      </label>
      <select
        id="shipping-rate-alt"
        onChange={handleRateChange}
        className="w-8/12 h-14 rounded p-2 border border-gray-300 focus:ring-blue-500 focus:border-blue-500"
      >
        <option disabled value="">
          请选择一个运费费率
        </option>
        {rates.map((rate, index) => (
          // 将索引 (加1以避开 disabled option) 作为 value
          // 也可以添加自定义 data-* 属性来存储更多信息
          <option value={index + 1} key={rate.id} data-id={rate.id} data-amount={rate.amount}>
            {rate.service} (${rate.amount})
          </option>
        ))}
      </select>

      {selectedRateDetails && (
        <div className="mt-4 p-4 border rounded bg-gray-50">
          <h3 className="text-md font-semibold">当前选择的费率 (替代方案):</h3>
          <p>服务: {selectedRateDetails.service}</p>
          <p>金额: ${selectedRateDetails.amount}</p>
          <p>ID: {selectedRateDetails.id}</p>
        </div>
      )}
    </div>
  );
}

export default ShippingRateSelectorAlternative;