问题
@override Widget build(BuildContext context) {
return WillPopScope(
onWillPop: () async {
return false;
},
child: Stack(
children: <Widget>[
DefaultTabController(
length: 5,
child: ChangeNotifierProvider(
builder: (context) => MySchedule(),
child: (
Scaffold(
appBar: AppBar(
actions: <Widget>[
Container(
width: MediaQuery.of(context).size.width,
child: Row(
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children: <Widget>[
GestureDetector(
onTap: () async{
await Navigator.of(context).push(
MaterialPageRoute(builder: (context){
return InApp();
})
);
final MySchedule schedules = Provider.of<MySchedule>(context);
schedules.numberOfCoins = 10;
},
child: Card(
child: Padding(
padding: const EdgeInsets.all(4.0),
child: Row(
children: <Widget>[
Consumer<MySchedule>(
builder: (context, coin, _) =>
buildCoinBar(coin),
),
SizedBox(
width: 2,
),
Stack(
children: <Widget>[
Image.asset('assets/coin2.png',
height: 22, width: 22,),
],
),
],
),
),
),
),
Image.asset('assets/LOGO.png'),
Consumer<MySchedule>(
builder: (context, userdata, _) =>
topRightElement(userdata, context),
),
],
),
)
],
automaticallyImplyLeading: false,
bottom: TabBar(
labelStyle: TextStyle(fontSize: 8),
tabs: [
Consumer<MySchedule>(
builder: (context, schedule, _) =>
buildNewCardNotification(schedule),
),
Tab(icon: Icon(Icons.star), text: 'Csapatom' ,),
Tab(icon: Icon(Icons.verified_user), text: 'Forduló',),
Tab(icon: Icon(Icons.stars), text: 'Kártyáim',),
Tab(icon: Icon(Icons.account_balance), text: 'Ligák',),
],
),
),
body: TabBarView(
children: [
Office(),
MyTeam(),
MatchListView(),
MyCardView(),
ChampionshipView2(),
],
),
)
),
),
),
Visibility(
visible: msgVisible,
child: SafeArea(
child: GestureDetector(
onTap: (){
setState(() {
msgVisible = false;
});
},
child: Padding(
padding: const EdgeInsets.all(2.0),
child: ClipRRect(
borderRadius: BorderRadius.circular(0.0),
child: Card(
shape: RoundedRectangleBorder(
side: new BorderSide(color: Colors.lightGreenAccent, width: 2.0),
borderRadius: BorderRadius.circular(16.0)),
elevation: 8,
color: Colors.black87,
child: Container(
height: 64,
width: MediaQuery.of(context).size.width,
child: Row(
children: <Widget>[
Padding(
padding: const EdgeInsets.all(10.0),
child: Image.asset('assets/LOGO.png', height:44),
),
Column(
crossAxisAlignment: CrossAxisAlignment.start,
mainAxisAlignment: MainAxisAlignment.spaceEvenly,
children: <Widget>[
Text(title, style: TextStyle(
fontSize: 16,
color: Colors.lightGreenAccent
),),
Text(body,
overflow: TextOverflow.ellipsis)
],
),
],
),
),
),
),
),
),
),
)
],
),
);
}
I try to modify the numberOfCoins variable, when I pop the InApp() class. But I have the following error:
[VERBOSE-2:ui_dart_state.cc(148)] Unhandled Exception: Error: Could not find the correct Provider above this FantasyNbi Widget
To fix, please:
- Ensure the Provider is an ancestor to this FantasyNbi Widget * Provide types to Provider * Provide types to Consumer * Provide types to Provider.of()
- Always use package imports. Ex:
import 'package:my_app/my_code.dart'; * Ensure the correctcontext` is being used.
回答1:
You need a builder bridge between ChangeNotifierProvider and Scaffold.
Provider package already has it's own builder called Consumer, you can use it like:
ChangeNotifierProvider(
builder: (context) => MySchedule(),
child: Consumer<MySchedule>(
builder: (context, provider, child) => Scaffold(....,
Check this link: https://pub.dev/packages/provider#reading-a-value
回答2:
According to the latest version of the Provider package, the builder() method of ChangeNotifierProvider was changed to create().
So editing Esen Mehmet's version, this will work instead:
ChangeNotifierProvider(
create: (context) => MySchedule(), //change builder to create
child: Consumer<MySchedule>(
builder: (context, provider, child) => Scaffold(....,
来源：https://stackoverflow.com/questions/57539094/could-not-find-the-correct-provider-flutter