Reactjs 当我选择下拉列表时，如何点击api来显示分支？ import React，{useState}来自“React”； 从“axios”导入axios； 常量应用=（）=>{ const[value，setValue]=使用状态（“”）； const[locations，setLocations]=useState（[]）； const handleSubmit=async（）=>{ 如果（值==“”）返回； let response=等待axios.get(`https://api2-4ofagodxfq-uc.a.run.app/locality?stateName=KARNATAKA&districtName=BANGALORE&pinCode=${value}`）； if（response.status==200）设置位置（response.data）； } 返回 卡纳塔克邦 班加罗尔 PINCODE:setValue（e.target.value）}/> 提交 {locations.map（（位置，索引）=>{ 返回{location} })} } 导出默认应用程序；

api在这里显示-

尝试在

select

onChange事件上调用api如何传递该值，我为select组件单击了dropdownwrite onChange事件

import React, { useState } from "react";
import axios from "axios";

const App = () => {
  const [value, setValue] = useState('');
  const [locations, setLocations] = useState([]);

  const handleSubmit = async () => {
    if (value === "") return;

    let response = await axios.get(`https://api2-4ofagodxfq-uc.a.run.app/locality?stateName=KARNATAKA&districtName=BANGALORE&pinCode=${value}`);
    if (response.status === 200) setLocations(response.data);
  }

  return <div>
    <select value="KARNATAKA">
      <option value="KARNATAKA">KARNATAKA</option>
    </select>
    <select value="BANGALORE">
      <option value="BANGALORE">BANGALORE</option>
    </select>
    PINCODE:<input type="text" onChange={e => setValue(e.target.value)} />
    <button type="button" onClick={handleSubmit}>SUBMIT</button>
    <select>
    {locations.map((location, index) => {
      return <option key={index}>{location}</option>
    })}
    </select>
  </div>
}

export default App;