第一种：

Navigator.of(context).pushNamed('/demo/page1',arguments: "flutter");

在PageState的Build函数里接收:

@override
  Widget build(BuildContext context) {

    var arguments = ModalRoute.of(context)!.settings.arguments;
    print("路由传递过来的参数：" + arguments.toString());
    if(arguments.toString() == "flutter"){
      _isRouteFromFlutter = true;
    }    return ...}

然而实际开发中遇到需要根据路由参数值，调用接口请求的情况，如果在build里获取已经晚了一步。所有第二种在构造方法里接收

第二种：

Navigator.push(
        context,
        MaterialPageRoute(
          builder: (context) => Page1(routeFromFlutter:true),
        ),
      );

接收参数：

class Page1 extends StatefulWidget {

  final bool routeFromFlutter;

  Page1({Key? key,required this.routeFromFlutter}) : super(key: key);

  @override
  _Page1PageState createState() => _Page1Page1State(routeFromFlutter);

}

class _Page1PageState extends State {

  bool _isRouteFromFlutter = false;
  _Page1PageState(this._isRouteFromFlutter);  ...
}