【发布时间】:2019-07-24 13:28:37
【问题描述】:
flutter 的新手有很多东西,现在才开始弄清楚它是 BLoC 模式,现在我遇到了问题 我不明白如何解决这个错误,似乎所有内容都写对了 这里是所有 BLoC 的通用接口
abstract class BlocBase {
void dispose();
}
class BlocProvider<T extends BlocBase> extends StatefulWidget {
BlocProvider({
Key key,
@required this.child,
@required this.bloc,
}) : super(key: key);
final T bloc;
final Widget child;
@override
_BlocProviderState<T> createState() => _BlocProviderState<T>();
static T of<T extends BlocBase>(BuildContext context) {
final type = _typeOf<BlocProvider<T>>();
BlocProvider<T> provider = context.ancestorWidgetOfExactType(type);
return provider.bloc;
}
static Type _typeOf<T>() => T;
}
class _BlocProviderState<T> extends State<BlocProvider<BlocBase>> {
@override
void dispose() {
widget.bloc.dispose();
super.dispose();
}
@override
Widget build(BuildContext context) {
return widget.child;
}
}
这是我使用 BLoC 的第二个文件,它给出了错误 这里我使用函数 validateAndCreateData 来添加门票
@override
Widget build(BuildContext context) {
final bloc = BlocProvider.of<TicketsBloc>(context);
return Scaffold(
drawer: MyDrawer(),
appBar: AppBar(
title: Text('Sports'),
backgroundColor: Colors.blueGrey[900],
// automaticallyImplyLeading: false,
actions: <Widget>[
IconButton(
icon: Icon(Icons.share),
tooltip: 'Share',
onPressed: () {
Navigator.of(context).pushNamed('/second_screen');
}),
IconButton(
icon: Icon(Icons.account_circle),
tooltip: 'Your account',
onPressed: () {
Navigator.of(context)
.pushReplacementNamed('/account_screen');
}),
IconButton(
icon: Icon(Icons.add),
tooltip: 'Add Tickets',
onPressed: () => validateAndCreateData(bloc),
)
]),
body: MyTab(),
);
}
void validateAndCreateData(TicketsBloc bloc) async {
bloc.createData(description, image, name, price);
}
【问题讨论】:
标签: firebase flutter google-cloud-firestore