DART

button shape flutter

shape: RoundedRectangleBorder(),
shape: BeveledRectangleBorder(),
shape: ContinuousRectangleBorder(),
shape: CircleBorder(),

raisedbutton shape flutter

shape: RoundedRectangleBorder(
  borderRadius: BorderRadius.circular(18.0),
  side: BorderSide(color: Theme.of(context).primaryColor),
),

raisedbutton flutter

RaisedButton(child: Text('Button'),
                onPressed: null,
                color: Colors.red,
                textColor: Colors.yellow,
                padding: EdgeInsets.fromLTRB(10, 10, 10, 10),
                splashColor: Colors.grey,
              )