错误：返回类型“CategoryState”不是“Widget”，这是闭包上下文所要求的

Question

I Tried to put the route to Another Class on the Same Page and wrote this code As mentioned in the flutter Doc. I get this

error: The return type CategoryState isn't a Widget , as required by the closure's context.

Page code

Navigation code

Answer 1

class CategoryState is not a widget it's just a Dart class you want to navigate to Category()

Answer 2

According to the documentation: https://flutter.dev/docs/cookbook/navigation/navigation-basics , the builder function of the MaterialPageRoute class should return a widget.Both StatelessWidget and StatefulWidget extend the Widget class and thus can be used here.

But in your case the CategoryState class does not extend any of them, and it's the reason you are having that error.

You need to use the Category class instead.

It should then look like:

PAGE:

class Category extends StatefulWidget {
  @override
  _CategoryState createState() => _CategoryState();
}

class _CategoryState extends State<Category> {
  @override
  Widget build(BuildContext context) {
      return Column(
          children: [
              Container(child: Text("Music")),
              Container(child: Text("Projects")),
              Container(child: Text("Essay")),
          ],
      );
  }
}

NAVIGATION

Navigator.push(
   context,
   MaterialPageRoute(builder: (context) => Category())
);

Furthermore, I would advise you to add a suffix to this class name (eg CategoryScreen) in order to avoid name conflicts in case you have another class (eg a model) with the same name.

Home my answer helps!