const [cityName, setCityName] = useState({ name: '', value: '' })
const [trainLine, setTrainLine] = useState({ name: '', value: '' })
const [station, setStation] = useState({ name: '', value: '' })
const [platform, setPlatform] = useState({ name: '', value: '' })
页面有四个逐级联动的下拉框(选择city=>选择trainline=>选择station=>选择platform),下级的选项获取依赖上级的选中值,如何优雅的处理state改变后的回调
useEffect?