Flutter中GoRouter传递布尔参数报错，咨询原因与解决方法

我尝试通过GoRouter传递bool类型参数时，收到以下错误提示：

参数类型String无法分配给参数类型"bool"

不确定错误来源，想确认：queryParams是否仅允许String类型？

代码片段 #

main.dart #

final GoRouter _router = GoRouter(routes: [
    GoRoute(name: 'home', path: '/home', builder: ((context, state) => Home(
                location: state.queryParams['location']!,
                time: state.queryParams['time']!,
                flag: state.queryParams['flag']!,
                isDaytime: state.queryParams['isDaytime']!,
            )   
        )   
    ),  
]);

world_time.dart #

class WorldTime {

  String _url = 'https://api-urlxxxxxxx';
  String location;
  String flag;
  String time = ''; 
  bool isDaytime = true;

  WorldTime({ required this.location, required this.flag }); 

  ...
}

home.dart #

class Home extends StatefulWidget {
    String location;
    String time;
    String flag;
    State isDaytime;

    Home({
        Key? key,
        required this.location,
        required this.time,
        required this.flag,
        required this.isDaytime,
    }) : super(key: key);

    @override
    // ignore: library_private_types_in_public_api
    _HomeState createState() => _HomeState();
}

loading.dart #

class Loading extends StatefulWidget {
    const Loading({Key? key}) : super(key: key);

    @override
    _LoadingState createState() => _LoadingState();
}


class _LoadingState extends State<Loading> {

    void setupWorldTime() async {
        WorldTime instance = WorldTime(location: 'London', flag: 'england.png');
        await instance.getTime();

        ...

        context.goNamed('home', queryParams: {
                'location': instance.location,
                'time': instance.time,
                'flag': instance.flag,
                'isDaytime': instance.isDaytime,
         }); 
     }
}

问题原因与解决方法 #

• queryParams仅支持String类型：URL查询参数本质都是字符串，GoRouter的queryParams要求所有值必须为String，直接传bool会触发类型错误，接收端直接赋值给bool变量也会报错。

• 修复步骤：

  1. 传递时转字符串：在loading.dart中将bool转为String：

     context.goNamed('home', queryParams: {
             'location': instance.location,
             'time': instance.time,
             'flag': instance.flag,
             'isDaytime': instance.isDaytime.toString(),
      }); 
     

  2. 接收时转bool：在main.dart中将字符串转回bool，可通过判断是否等于'true'实现：

     final GoRouter _router = GoRouter(routes: [
         GoRoute(name: 'home', path: '/home', builder: ((context, state) => Home(
                     location: state.queryParams['location']!,
                     time: state.queryParams['time']!,
                     flag: state.queryParams['flag']!,
                     isDaytime: state.queryParams['isDaytime'] == 'true',
                 )   
             )   
         ),  
     ]);
     

  3. 修正home.dart类型错误：isDaytime的类型误写为State，需改成bool：

     class Home extends StatefulWidget {
         String location;
         String time;
         String flag;
         bool isDaytime;
     
         Home({
             Key? key,
             required this.location,
             required this.time,
             required this.flag,
             required this.isDaytime,
         }) : super(key: key);
     
         @override
         // ignore: library_private_types_in_public_api
         _HomeState createState() => _HomeState();
     }
     

内容的提问来源于stack exchange，提问作者Duddy67