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

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I have 2 screens in my Flutter app: list of records and screen for creating and editing records.

If I pass object to second screen that means I am going to edit this and if I pass null it means that I am creating new item. Editing screen is Stateful widget and I am not sure how to use this approach https://flutter.io/cookbook/navigation/passing-data/ for my case.

class RecordPage extends StatefulWidget {
  final Record recordObject;

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

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

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

How can I access recordObject inside _RecordPageState?

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
   .....
  }
}

Passing Data to a Stateful Widget, Don't pass parameters to State using it's constructor. You should only access these using this.widget.myField . Not only editing the constructor  Passing data to StatefulWidget and accessing it in it’s state in Flutter 0 I have 2 screens in my Flutter app: list of records and screen for creating and editing records.

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
   //.....
  }
}

How to pass data from Stateful Widget Constructor to its state class , In this article, we will see how to pass data from outside of Stateful Widget to its internal State class through its constructor. Therefore, Stateful. Passing data through the widget constructor The simplest way to send data from a widget to another is by its constructor. Let’s say, for example, we need to pass an instance of the above Data class

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")));

Simple ways to pass to and share data with widgets/pages, The simplest way to send data from a widget to another is by its constructor. Every widget along the tree can access to the data provided by our singletons/​appdata.dart';class AppDataPage extends StatefulWidget { @  StatefulWidget instances themselves are immutable and store their mutable state either in separate State objects that are created by the createState method, or in objects to which that State subscribes, for example Stream or ChangeNotifier objects, to which references are stored in final fields on the StatefulWidget itself.

Passing data to StatefulWidget and accessing it in it's state in Flutter, Passing data to StatefulWidget and accessing it in it's state in Flutter. flutter pass data to statelesswidget flutter pass data between widgets flutter pass parameter  MyApp is StatelessWidget which will host our StateFulWidget as the first page, that's why we are passing MainPage (to be created) as object: Now right click on lib folder and click on new and add package to folder by name widgets. Add new dart file by name mainpage.dart, which will have code of our Stateful widget.

Passing Data to a Stateful Widget, Passing Data to Stateful Widget, So In This Video We Are Going To Learn How Passing data to StatefulWidget and accessing it in it's state in Flutter , To use  Navigate and pass data to the detail screen. With a DetailScreen in place, you’re ready to perform the Navigation. In this example, navigate to the DetailScreen when a user taps a todo in the list. Pass the todo to the DetailScreen. To capture the user’s tap, write an onTap () callback for the ListTile widget.

Passing data to StatefulWidget and accessing it in , Passing data to StatefulWidget and accessing it in it's state in Flutter. To use recordObject in _RecordPageState, you have to just write  Stateful Widget. Some other Widgets will handle some inner data that will change during the Widget’s lifetime. This data hence becomes dynamic. The set of data held by this Widget and which may vary during the lifetime of this Widget is called a State. These Widgets are called Stateful Widgets.

Comments
  • Possible duplicate of Passing Data to a Stateful Widget
  • how can we use 'recordObject' variable value in a function of _RecordPageState class?
  • Does this answer your question? Pass StatefulWidget data to the State class without using constructor
  • Those who are new to Flutter, do not forget to define widget like '@override RecordPage get widget => super.widget;'
  • @hhk Why is that necessary?
  • Should't the recordObject be part of the State class? Logically, having it in StatefulWidget is incorrect (in terms of cohesion). Besides, all fields of StatefulWidget should be immutable - what if you want to change the recordObject reference?
  • I have exactly the same and it's not working doing something like Text(widget.recordObject), it says that my var is null
  • how can we use 'recordObject' variable value in a function of _RecordPageState class?
  • Please explain why this is a statefull widget.
  • @atilkan because OP initial script is a StatefulWidget, he just added some lines to fit the needs.
  • I do not think that having recordObject field both in State and StatefulWidget classes is such a good idea (even though I saw tutorials doing exactly this). The approach of accessing fields of StatefulWidget by using widget field of State class seem like a more correct approach (even though it has its own problems)