初始化路由

 MaterialApp(routes: <String, WidgetBuilder>{"/Second": (BuildContext context){return Second("");}},

跳转传参数

String va = await Navigator.of(context).push(MaterialPageRoute(builder: (content) {return Second( 'demo');
},
));print('回掉=====$va');

class Second extends StatelessWidget {final String str;const Second(this.str, {Key? key}) : super(key: key);@overrideWidget build(BuildContext context) {return ElevatedButton(onPressed: () {Navigator.of(context).pop("asdadad");},child: Text("第二个${str}"),);}
}