Parse arguments with Navigator.push shows error too many positional arguments: 0 expected, but 1 found

Question

I want to parse arguments with Navigator.push() to my other dart file.

Because I want to send the path of the selected song in songlist, to the music player main UI (For Playing)

[ songlist.dart ]

child:ListView.builder(
                      itemCount: getSongList()[0].length,
                      itemBuilder: (BuildContext context, int index) {
                        return ListTile(
                          title: Text(getSongList()[1][index].split('/').last,style:
                          const TextStyle(
                              fontSize: 21
                          ),),
                          leading: IconButton(onPressed: (){
                            Navigator.push(context,MaterialPageRoute(builder: (context) => music_player()));
                          },
                              icon: Icon(Icons.my_library_music)),
                        );
                      }
                  )
              ),

[ musicplayer.dart ]

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

  @override
  State<music_player> createState() => _music_playerState();
}

class _music_playerState extends State<music_player> {
  // codes
}

Just wanna know how to parse arguments from my first file to second file. If I pass arguments there will be an error:

too many positional arguments: 0 expected, but 1 found.

Thanks in advance.

Answer 1

you need to add parameter(selectedSongs) in widget like this:

class MusicPlayer extends StatefulWidget {
  final selectedSongs;

  const MusicPlayer({
    Key? key,
    this.selectedSongs,
  }) : super(key: key);

  @override
  State<MusicPlayer> createState() => _MusicPlayerState();
}

class _MusicPlayerState extends State<MusicPlayer> {
  @override
  Widget build(BuildContext context) {
    return const Placeholder();
  }
}

this way you can use in Navigator.push:

Navigator.push(context,MaterialPageRoute(builder: (context) => MusicPlayer(selectedSongs: selectedsongList,))));

Answer 2

If your want to pass arguments with Navigator the correct way is:

-Register the widget in the routes:

MaterialApp(
routes: {
    ExtractArgumentsScreen.routeName: (context) =>
        const ExtractArgumentsScreen(),
  },
)

-Navigate to the widget:

Navigator.pushNamed(
  context,
  ExtractArgumentsScreen.routeName,
  arguments: // whatever you want to pass,
);

And inside your next page widget:

    @override
    Widget build(BuildContext context) {
      final args = ModalRoute.of(context)!.settings.arguments;
      return Scafold( ... );
    }

All information here: https://docs.flutter.dev/cookbook/navigation/navigate-with-arguments