flutterDemo/app/lib/main.dart

import 'package:flutter/material.dart';
import 'package:english_words/english_words.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
        title: 'Flutter Demo',
        theme: ThemeData(
          // This is the theme of your application.
          //
          // Try running your application with "flutter run". You'll see the
          // application has a blue toolbar. Then, without quitting the app, try
          // changing the primarySwatch below to Colors.green and then invoke
          // "hot reload" (press "r" in the console where you ran "flutter run",
          // or simply save your changes to "hot reload" in a Flutter IDE).
          // Notice that the counter didn't reset back to zero; the application
          // is not restarted.
          primarySwatch: Colors.blue,
          // This makes the visual density adapt to the platform that you run
          // the app on. For desktop platforms, the controls will be smaller and
          // closer together (more dense) than on mobile platforms.
          visualDensity: VisualDensity.adaptivePlatformDensity,
        ),
        // home: MyHomePage(title: 'Flutter Demo Home Page'),
        routes: {
          "new_page": (context) => NewRoute(),
          "/": (context) => MyHomePage(title: '首页'), //注册首页路由
        },
        onGenerateRoute: (RouteSettings settings) {
          return MaterialPageRoute(builder: (context) {
            String routeName = settings.name;
            print(routeName);
            // 如果访问的路由页需要登录，但当前未登录，则直接返回登录页路由，
            // 引导用户登录；其它情况则正常打开路由。
          });
        });
    // 路由钩子
  }
}

class MyHomePage extends StatefulWidget {
  MyHomePage({Key key, this.title}) : super(key: key);

  // This widget is the home page of your application. It is stateful, meaning
  // that it has a State object (defined below) that contains fields that affect
  // how it looks.

  // This class is the configuration for the state. It holds the values (in this
  // case the title) provided by the parent (in this case the App widget) and
  // used by the build method of the State. Fields in a Widget subclass are
  // always marked "final".

  final String title;

  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  int _counter = 0;
// 111
  void _incrementCounter() {
    setState(() {
      // This call to setState tells the Flutter framework that something has
      // changed in this State, which causes it to rerun the build method below
      // so that the display can reflect the updated values. If we changed
      // _counter without calling setState(), then the build method would not be
      // called again, and so nothing would appear to happen.
      _counter++;
    });
  }

  @override
  Widget build(BuildContext context) {
    // This method is rerun every time setState is called, for instance as done
    // by the _incrementCounter method above.
    //
    // The Flutter framework has been optimized to make rerunning build methods
    // fast, so that you can just rebuild anything that needs updating rather
    // than having to individually change instances of widgets.
    return Scaffold(
      appBar: AppBar(
        // Here we take the value from the MyHomePage object that was created by
        // the App.build method, and use it to set our appbar title.
        title: Text(widget.title),
      ),
      body: Center(
        // Center is a layout widget. It takes a single child and positions it
        // in the middle of the parent.
        child: Column(
          // Column is also a layout widget. It takes a list of children and
          // arranges them vertically. By default, it sizes itself to fit its
          // children horizontally, and tries to be as tall as its parent.
          //
          // Invoke "debug painting" (press "p" in the console, choose the
          // "Toggle Debug Paint" action from the Flutter Inspector in Android
          // Studio, or the "Toggle Debug Paint" command in Visual Studio Code)
          // to see the wireframe for each widget.
          //
          // Column has various properties to control how it sizes itself and
          // how it positions its children. Here we use mainAxisAlignment to
          // center the children vertically; the main axis here is the vertical
          // axis because Columns are vertical (the cross axis would be
          // horizontal).
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            Text(
              '你已经按了很多次了开始吧:',
            ),
            Text(
              '$_counter',
              style: Theme.of(context).textTheme.headline4,
            ),
            FlatButton(
              child: Text("open new route"),
              textColor: Colors.red,
              onPressed: () {
                // 普通路由导航
                // Navigator.pushNamed(context, "new_page");
                // 在打开路由时传递参数
                Navigator.of(context).pushNamed("new_page", arguments: "hi");
                //导航到新路由
                // Navigator.push(
                //     context,
                //     MaterialPageRoute(
                //         builder: (context) {
                //           return NewRoute();
                //         },
                //         maintainState: false,
                //         fullscreenDialog: false));
              },
            ),
            RouterTestRoute(),
            RandomWordsWidget()
          ],
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: _incrementCounter,
        tooltip: 'Increment',
        child: Icon(Icons.add),
      ), // This trailing comma makes auto-formatting nicer for build methods.
    );
  }
}

// 新的路由
class NewRoute 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" + args),
      ),
      body: Center(
          child: Column(
        children: [
          Text("This is new route" + args),
          RandomWordsWidget(),
          Image(
            image: AssetImage("images/avatar.png"),
            width: 100.0,
            color: Colors.blue,
            colorBlendMode: BlendMode.difference,
          ),
          // Image(
          //   image: NetworkImage(
          //       "https://avatars2.githubusercontent.com/u/20411648?s=460&v=4"),
          //   width: 100.0,
          //   color: Colors.blue,
          //   // colorBlendMode: BlendMode.difference,
          // ),
          // Image.network(
          //   "https://avatars2.githubusercontent.com/u/20411648?s=460&v=4",
          //   width: 100.0,
          // )
        ],
      )),
    );
  }
}

class TipRoute extends StatelessWidget {
  TipRoute({
    Key key,
    @required this.text, // 接收一个text参数
  }) : super(key: key);
  final String text;

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text("提示"),
      ),
      body: Padding(
        padding: EdgeInsets.all(18),
        child: Center(
          child: Column(
            children: <Widget>[
              Text(text),
              RaisedButton(
                onPressed: () => Navigator.pop(context, "我是返回值"),
                child: Text("返回"),
              )
            ],
          ),
        ),
      ),
    );
  }
}

class RouterTestRoute extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Center(
      child: RaisedButton(
        onPressed: () async {
          // 打开`TipRoute`，并等待返回结果
          var result = await Navigator.push(
            context,
            MaterialPageRoute(
              builder: (context) {
                return TipRoute(
                  // 路由参数
                  text: "我是提示xxxx",
                );
              },
            ),
          );
          //输出`TipRoute`路由返回结果
          print("路由返回值: $result");
        },
        child: Text("打开提示页"),
      ),
    );
  }
}

class RandomWordsWidget extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    // 生成随机字符串
    final wordPair = new WordPair.random();
    return Padding(
      padding: const EdgeInsets.all(8.0),
      child: new Text(wordPair.toString()),
    );
  }
}