The AppBarDesign can't be assigned to the parameter type 'PreferredSizeWidget'

Question

Anyone please give some information why this is happening?

When I try to add a class AppBarDesign which implements appBar flutter is gi

Answer 1

You can also use following way to design your appbar in separate file and then use it in your whole app.

Widget Custom_Appbar(){
  return AppBar(
        shape: RoundedRectangleBorder(
            borderRadius: BorderRadius.vertical(bottom: Radius.circular(20))),
        title: Text(
          'Decimal to Binary & Vice Versa',
          style: TextStyle(fontWeight: FontWeight.w400, fontSize: 19),
        ));
}

And then use it like this

return Scaffold(
      appBar: Custom_Appbar(),
)