关于flutter:flutter-路由跳转

单页面路由跳转时留神不要有两个 materialapp，因为导航是依赖于这个的，有两个，就会有两个导航

一、两种路由传参办法：DetailScreen 跳转的路由组件

间接向路由子组件构造函数传参

Navigator.push(
    context,
    MaterialPageRoute(builder: (context) => DetailScreen(todo: todos[index]),
      ),
 );

通过 RouteSettings 传递参数

Navigator.push(
     context,
      MaterialPageRoute(builder: (context) => DetailScreen(),
            settings: RouteSettings(arguments: todos[index],
             ),
        ),
 );

二、定义路由：
1、在 MaterialApp 中增加属性：

 initialRoute 和 routes 来定义咱们的路由
new MaterialApp(
      initialRoute: '/',
      routes: {'/': (context) => TodosScreen(todos: todos),
        '/detail': (context) => DetailScreen(),},
      title: 'ssss',
);

但要留神的是：当应用 initialRoute 时，须要确保你没有同时定义 home 属性。

2、给特定的 route 传参：
1) 定义须要传递的参数

class ScreenArguments {
  final String title;
  final String message;
  ScreenArguments(this.title, this.message);
}

2) 创立组件来获取参数

class ExtractArgumentsScreen extends StatelessWidget {
  static const routeName = '/extractArguments';
  @override
  Widget build(BuildContext context) {final ScreenArguments args = ModalRoute.of(context).settings.arguments;
    return Scaffold();}
}

3) 把组件注册到路由表中

MaterialApp(
  routes: {ExtractArgumentsScreen.routeName: (context) => ExtractArgumentsScreen(),},
);

4) 导航到组件

RaisedButton(onPressed: () {
    Navigator.pushNamed(
      context,
      ExtractArgumentsScreen.routeName,
      arguments: ScreenArguments(
        'Extract Arguments Screen',
        'This message is extracted in the build method.',
      ),
    );
  },
),

5) onGenerateRoute 提取参数

MaterialApp(onGenerateRoute: (settings) {if (settings.name == PassArgumentsScreen.routeName) {
      final ScreenArguments args = settings.arguments;
      return MaterialPageRoute(builder: (context) {
          return PassArgumentsScreen(
            title: args.title,
            message: args.message,
          );
        },
      );
    }
  },
);