bloc结合rxdart的一些代码

bloc_provider.dart

import 'package:flutter/material.dart';
import 'package:bloc_demo/rxdart/blocs/count_bloc.dart';

class BlocProvider extends InheritedWidget {
  final CountBLoC bLoC = CountBLoC();

  BlocProvider({Key key, Widget child}) : super(key: key, child: child);

  @override
  bool updateShouldNotify(_) => true;

  static CountBLoC of(BuildContext context) =>
      (context.inheritFromWidgetOfExactType(BlocProvider) as BlocProvider).bLoC;
}

count_bloc.dart

import 'package:rxdart/rxdart.dart';
import 'dart:async';

class CountBLoC {
  int _count = 0;
  var _subject = BehaviorSubject();

  Stream get stream => _subject.stream;
  int get value => _count;

  void increment() => _subject.add(++_count);

  void dispose() {
    _subject.close();
  }
}

top_page.dart

import 'package:flutter/material.dart';
import 'package:bloc_demo/rxdart/blocs/bloc_provider.dart';
import 'under_page.dart';

class TopPage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    final bloc = BlocProvider.of(context);

    return Scaffold(
      appBar: AppBar(
        title: Text('Top Page'),
      ),
      body: Center(
        child: StreamBuilder(
            stream: bloc.stream,
            initialData: bloc.value,
            builder: (BuildContext context, AsyncSnapshot snapshot) {
              return Text(
                'You hit me: ${snapshot.data} times',
                style: Theme.of(context).textTheme.display1,
              );
            }),
      ),
      floatingActionButton: FloatingActionButton(
          child: Icon(Icons.navigate_next),
          onPressed: () =>
              Navigator.of(context).push(MaterialPageRoute(builder: (context) => UnderPage()))),
    );
  }
}

under_page.dart

import 'package:flutter/material.dart';
import 'package:bloc_demo/rxdart/blocs/bloc_provider.dart';

class UnderPage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    final bloc = BlocProvider.of(context);

    return Scaffold(
      appBar: AppBar(
        title: Text('Under Page'),
      ),
      body: Center(
        child: StreamBuilder(
            stream: bloc.stream,
            initialData: bloc.value,
            builder: (context, snapshot) => Text(
                  "You hit me: ${snapshot.data} times",
                  style: Theme.of(context).textTheme.display1,
                )),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: () => bloc.increment(),
        child: Icon(Icons.add),
      ),
    );
  }
}

最后，最重要的，入口处：

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return BlocProvider(
      child: MaterialApp(
        title: 'scoped',
        theme: ThemeData.dark(),
        home: TopPage(),
      ),
    );
  }
}