Dart 中可扩展类附近的尖括号是什么意思？

Question

For what are using angle brackets <> in class inheritance declaration in Dart language?

Code example from Flutter's project code:

class _HomeState extends State<Home> {
...
}

The code tells that class _HomeState extends class State , but for what is <Home> ?

Answer 1

Official docs says that State<T extends StatefulWidget> class is The logic and internal state for a StatefulWidget .

so in your case we will have:

class Home extends StatefulWidget {
  @override
  _HomeState createState() => _HomeState();
}

class _HomeState extends State<Home> {
  @override
  Widget build(BuildContext context) {
    return Container();
  }
}

Official documentation: State Class StatefulWidget Class