State Management Widget

In Flutter, there are mainly two types of widget:

• StatelessWidget
• StatefulWidget

StatefulWidget

A StatefulWidget has state information. It contains mainly two classes: the state object and the widget. It is dynamic because it can change the inner data during the widget lifetime. This widget does not have a build() method. It has createState() method, which returns a class that extends the Flutters State Class. The examples of the StatefulWidget are Checkbox, Radio, Slider, InkWell, Form, and TextField.

Example

class Car extends StatefulWidget {  
  const Car({ Key key, this.title }) : super(key: key);   
  
  @override  
  _CarState createState() => _CarState();  
}  
  
class _CarState extends State<Car> {  
  @override  
  Widget build(BuildContext context) {  
    return Container(  
      color: const Color(0xFEEFE),  
           child: Container(  
            child: Container( //child: Container() )  
        )  
    );  
  }  
}  

StatelessWidget

The StatelessWidget does not have any state information. It remains static throughout its lifecycle. The examples of the StatelessWidget are Text, Row, Column, Container, etc.

Example

class MyStatelessCarWidget extends StatelessWidget {  
  const MyStatelessCarWidget ({ Key key }) : super(key: key);  
  
  @override  
  Widget build(BuildContext context) {  
    return Container(color: const Color(0x0xFEEFE));  
  }  
}