Difference between onGenerateRoute and routes in Flutter

Question

What is the benefit or use case of onGenerateRoute and routes in Flutter.

In my application in first page inside MaterialApp we can define rout

Answer 1

My solution is to re-assign the settings of MaterialPageRoute.

eg: //配置路由

final routes = {
  '/': (context) => MainPage(),
};

// 统一处理

var onGenerateRoute = (RouteSettings settings) {
    final String name = settings.name;
      final Function pageContentBuilder = routes[name];
      if (pageContentBuilder != null) {
        if (settings.arguments != null) {
          final Route route = MaterialPageRoute(
              settings: settings,
              builder: (context) => pageContentBuilder(context, arguments: settings.arguments));
          return route;
        } else {
          final Route route =
              MaterialPageRoute(settings: settings,
                  builder: (context) => pageContentBuilder(context));
          return route;
        }
      }
    };