1.引用 google 状态管理库

provider: ^3.0.0+1

2.自定义model 继承 ChangeNotifier

class SkinModel extends ChangeNotifier {

MaterialColor color =Colors.blue;

}

3.使用 ChangeNotifierProvider

void main() => runApp(ChangeNotifierProvider(

builder: (context) =>SkinModel(),

      child:MyApp(),

    ));

class MyApp extends StatelessWidget {

// This widget is the root of your application.

  SkinModel skinModel;

  @override

  Widget build(BuildContext context) {

return MaterialApp(

title:'Flutter Demo',

      theme:ThemeData(

primarySwatch:Provider.of(context).color,

      ),

      home:MyHomePage(),

    );

  }

}

4. 修改样式

void _changeState() {

SkinModel skinModel =Provider.of(context)..color =Colors.red;

  skinModel.notifyListeners();

}