How to make widget without '?' and 'required'-CodePudding

so im working on company project and realize the widget doesn't need Key? and required costructor, and when i try to make it like that it occur red underline.

my project i want to remove the required and '?'

example of what i want

CodePudding user response：

you have probably defined height as final and that's why it is asking it.

define height as

double? height

CodePudding user response：

It should view like that:

class CustomButton extends StatelessWidget {
  final double? height;
  final double width;
  final String title;
  final double margin;
  final Function() onPressed;
  const CustomButton ({
  Key? key,
  this.height,
  required this.width,
  required this.title,
  required this.margin,
  required this.onPressed,
  }) : super (key: key);
}

CodePudding user response：

You have to pass an initial value for the CustomButton height property.

class CustomButton extends StatelessWidget {
  final double height;
  final double width;
  final String title;
  final double margin;
  final Function() onPressed;
  const CustomButton ({
  Key? key,
  this.height = 100,
  required this.width,
  required this.title,
  required this.margin,
  required this.onPressed,
  }) : super (key: key);
}