Passing data to StatefulWidget and accessing it in it's state in Flutter

To use recordObject in _RecordPageState, you have to just write widget.objectname like below

class _RecordPageState extends State<RecordPage> {
  @override
  Widget build(BuildContext context) {
   .....
   widget.recordObject
   .....
  }
}

class RecordPage extends StatefulWidget {
  final Record recordObject;

  RecordPage({Key key, @required this.recordObject}) : super(key: key);

  @override
  _RecordPageState createState() => new _RecordPageState(recordObject);
}

class _RecordPageState extends State<RecordPage> {
  Record  recordObject
 _RecordPageState(this. recordObject);  //constructor
  @override
  Widget build(BuildContext context) {.    //closure has access
   //.....
  }
}

Full Example

You don't need to pass parameters to State using it's constructor. You can easily access these using widget.myField.

class MyRecord extends StatefulWidget {
  final String recordName;
  const MyRecord(this.recordName);

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

class MyRecordState extends State<MyRecord> {
  @override
  Widget build(BuildContext context) {
    return Text(widget.recordName); // Here you direct access using widget
  }
}

Pass your data when you Navigate screen :

 Navigator.of(context).push(MaterialPageRoute(builder: (context) => MyRecord("WonderWorld")));