flutter 编写组件时，碰到奇怪报错，为什么？

Question

city_selecter.dart

import 'package:city_pickers/city_pickers.dart';
import 'package:flutter/material.dart';

class CitySelecter extends StatefulWidget{
  final Function callback;
  const CitySelecter({Key? key, required this.callback}) : super(key: key);

  @override
  State<StatefulWidget> createState() => _state();
}

class _state extends State<CitySelecter>{
  String text = "请选择";
  // Result result;
  Result result = Result();
  
  show(BuildContext context, Function onClick) async {
    Result? tempResult = await CityPickers.showCitiesSelector(
          context: context, 
          hotCities: [
            HotCity(id: 110100, name: '北京'),
            HotCity(id: 310100, name: '上海'),
            HotCity(id: 440100, name: '广洲'),
            HotCity(id: 440300, name: '深圳'),
          ],);

    if (tempResult == null) {
      return;
    }

    onClick(tempResult);
    // return tempResult;
  }

  @override
  Widget build(BuildContext context) {
    
    // print(list);
    // TODO: implement build
    return InkWell(
      onTap: (){
        show(context, (e)=>{
          // print(e)
          setState(() {
            result = e;
          });
          widget.callback(e);
        });

      },
      child: Row(
        children: [
          Text(result.cityName??text, style: const TextStyle(fontSize: 14),),
          const Icon(Icons.arrow_forward_ios, size: 16,)
        ],
      ),
    );
  }
}

报错如图，应该是一个语法错误，但我尝试去除 ; ，则下一行又报错，我在其它地方有类似的写法，但并没有报错

下面是同样类型语法的地方，但未报错。

Answer 1

show(context, (e)=>{
          // print(e)
          setState(() {
            result = e;
          });
          widget.callback(e);
        });

去掉 => 号

Answer 2

箭头函数的返回只能是一条语句,多条语句的话不能使用箭头函数.
所以你添加分号就代表了多条语句,所以报错了,有以下方式可修改;
1.改为普通写法,也即是去掉箭头.
2.通过逗号分隔语句;
示例:onPressed: () => {debugPrint('xxx'), debugPrint('yyy')}