I'm using Flutter and Block StateManagement

The error occurred when I passed an argument to a route and it gives me this error :

The argument type 'Object?' can't be assigned to the parameter type 'EditProfileScreenArgs?

you can see the error in custom_router.dart

custom_router.dart

import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
import 'package:flutter_insta_bloc_firebase/screens/screens.dart';

class CustomRouter {
  static Route onGenerateRout(RouteSettings settings) {
    print('Route : ${settings.name}');
    switch (settings.name) {
      case '/':
        return MaterialPageRoute(
            settings: const RouteSettings(name: '/'),
            builder: (_) => Scaffold());

      case SplashScreen.routeName:
        return SplashScreen.route();

      case LoginScreen.routeName:
        return LoginScreen.route();

      case NavScreen.routeName:
        return NavScreen.route();

      default:
        return _errorRoute();
    }
  }

  static Route onGenerateNestedRout(RouteSettings settings) {
    print('Nested Route : ${settings.name}');
    switch (settings.name) {
      case EditProfileScreen.routeName:
    return EditProfileScreen.route(args: settings.arguments);

      default:
        return _errorRoute();
    }
  }

  static Route _errorRoute() {
    return MaterialPageRoute(
        settings: const RouteSettings(name: '/error'),
        builder: (_) => Scaffold(
              appBar: AppBar(
                title: const Text('Error'),
              ),
              body: const Center(
                child: Text('Some Thing went wrong!'),
              ),
            ));
  }
}

profile_button.dart

// ignore_for_file: deprecated_member_use

import 'package:flutter/material.dart';
import 'package:flutter_insta_bloc_firebase/screens/screens.dart';

class ProfileButton extends StatelessWidget {
  final bool isCurrentUser;
  final bool isFollowing;

  const ProfileButton(
      {Key? key, required this.isCurrentUser, required this.isFollowing})
      : super(key: key);

  @override
  Widget build(BuildContext context) {
    return isCurrentUser
        ? FlatButton(
            color:
                isFollowing ? Colors.grey[300] : Theme.of(context).primaryColor,
            onPressed: () => Navigator.of(context).pushNamed(
                EditProfileScreen.routeName,
                arguments: EditProfileScreenArgs(
                    context: context)), //send context for editProfileScreen
            child: Text(
              'Edite Profile',
              style: TextStyle(
                  color: isFollowing ? Colors.black : Colors.white,
                  fontSize: 16.0),
            ))
        : FlatButton(
            color:
                isFollowing ? Colors.grey[300] : Theme.of(context).primaryColor,
            onPressed: () {},
            child: Text(
              isFollowing ? 'Unfollow' : 'Follow',
              style: TextStyle(
                  color: isFollowing ? Colors.black : Colors.white,
                  fontSize: 16.0),
            ));
  }
}

Edit_Profile_screen.dart

import 'dart:js';

import 'package:flutter/material.dart';
import 'package:flutter_bloc/flutter_bloc.dart';
import 'package:flutter_insta_bloc_firebase/repository/repository.dart';
import 'package:flutter_insta_bloc_firebase/screens/edit_profile/cubit/edite_profile_cubit.dart';
import 'package:flutter_insta_bloc_firebase/screens/pages/profile/bloc/profile_bloc.dart';
import 'package:meta/meta.dart';

//with this class we can pass argumentfor go to profile_btn
class EditProfileScreenArgs {
  final BuildContext context;

  const EditProfileScreenArgs({required this.context});
}

class EditProfileScreen extends StatelessWidget {
  static const String routeName = '/editProfile';

  static Route route({EditProfileScreenArgs? args}) {
    return MaterialPageRoute(
        settings: const RouteSettings(name: routeName),
        builder: (context) => BlocProvider<EditeProfileCubit>(
              create: (context) => EditeProfileCubit(
                  userReposirory: context.read<UserReposirory>(),
                  storageRepository: context.read<StorageRepository>(),
                  profileBloc: args!.context.read<ProfileBloc>()),
              child: EditProfileScreen(),
            ));
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('Edit Profile'),
      ),
    );
  }
}

CodePudding user response：

You need to tell the type of the passing argument otherwise it will be consider as generic of type Object?. Try this code in onGenerateNestedRout method of your custom_router.

switch (settings.name) {
      case EditProfileScreen.routeName:
    return EditProfileScreen.route(args: settings.arguments as EditProfileScreenArgs?);

      default:
        return _errorRoute();
    }