Flutter笔记之路由参数传递（命名路由参数）

修改MyApp ，注册新路由："new_page2":(context)=>EchoRoute(),

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      routes: {
        //"new_page":(context)=>NewRoute(),
        "new_page2":(context)=>EchoRoute(),
      },
      home: MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

新建路由界面,获取路由参数

class EchoRoute extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    //获取路由参数
   var args=ModalRoute.of(context).settings.arguments;
    return Scaffold(
      appBar: AppBar(
        title: Text("New route"),
      ),
      body: Center(
	//直接展示参数内容
        child: Text(args),
      ),
    );
}}

在打开路由时传递参数

class _MyHomePageState extends State<MyHomePage> {
  int _counter = 0;
  void _incrementCounter() {
    setState(() {
      _counter++;
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            Text(
              'You have pushed the button this many times:',
            ),
            Text(
              '$_counter',
              style: Theme.of(context).textTheme.display1,
            ),
            FlatButton(
              child: Text("open new route"),
              textColor: Colors.blue,
              onPressed: () {
		  //在打开路由时传递参数		
                  Navigator.of(context).pushNamed("new_page2", arguments: "参数传递到子页面");
//                Navigator.pushNamed(context, "new_page");
//                Navigator.push(context,
//                    new MaterialPageRoute(builder: (context) {
//                  return new NewRoute();
//                }));
              },
            ),
          ],
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: _incrementCounter,
        tooltip: 'Increment',
        child: Icon(Icons.add),
      ), // This trailing comma makes auto-formatting nicer for build methods.
    );
  }
}