flutter: why I cannot use the final member field as the padding of widget?

Question

I write the following widget:

class Bottombar extends StatelessWidget {
  final double padding;
  Bottombar({@required this.padding});
  @override
  Widget build(BuildContext context) {
    return new Container(
      padding: const EdgeInsets.all(padding), child: new Text('Test'),);
  }
}

However, it reports compiling error that the padding parameter must be constant expressions. Why cannot use the final member field as the parameter of widget padding? For what reason?

The flutter version is beta 0.3.1

Answer 1

The problem is you're using const to create the EdgeInsets but then passing a variable padding.

Remove const and it should work.