firebase - 错误：云找不到正确的提供者> 在此 BrewList 小部件上方
问题描述
我正在尝试从 Firestore 检索基于自动更新的 stepcountvalue。不知何故有一个错误，我只是不知道为什么......
这是我的 main.dart
import 'dart:math';
import 'package:flutter/material.dart';
import 'package:flutter_testing/models/brew.dart';
import 'package:flutter_testing/models/user.dart';
import 'package:flutter_testing/screens/Pages/page.dart';
import 'package:flutter_testing/screens/wrapper.dart';
import 'package:flutter_testing/services/auth.dart';
import 'package:flutter_testing/services/database.dart';
import 'dart:async';
import 'package:percent_indicator/circular_percent_indicator.dart';
import 'package:font_awesome_flutter/font_awesome_flutter.dart';
import 'package:pedometer/pedometer.dart';
import 'package:provider/provider.dart';
void main() => runApp(new NewApp());
class NewApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return StreamProvider<User>.value(
value: AuthService().user,
child: MaterialApp(
home: Wrapper(),
),
);
}
}
class MyApp extends StatefulWidget {
@override
_MyAppState createState() => _MyAppState();
}
class _MyAppState extends State<MyApp> {
final AuthService _auth = AuthService();
String muestrePasos = "";
String _km = "Unknown";
String _calories = "Unknown";
String stepCountValue = 'Unknown';
String _showcoin = '0';
StreamSubscription<int> _subscription;
double _numerox; //numero pasos
double _convert;
double _kmx;
double burnedx;
double _coin;
double _porciento;
// double percent=0.1;
@override
void initState() {
super.initState();
//initPlatformState();
setUpPedometer();
}
//inicia codigo pedometer
void setUpPedometer() {
Pedometer pedometer = new Pedometer();
_subscription = pedometer.stepCountStream.listen(_onData,
onError: _onError, onDone: _onDone, cancelOnError: true);
}
void _onData(int stepCountValue1) async {
// print(stepCountValue); //impresion numero pasos por consola
setState(() {
stepCountValue = "$stepCountValue1";
// print(stepCountValue);
});
var dist = stepCountValue1; //pasamos el entero a una variable llamada dist
double y = (dist + .0); //lo convertimos a double una forma de varias
setState(() {
_numerox = y; //lo pasamos a un estado para ser capturado ya convertido a double
});
var long3 = (_numerox);
long3 = num.parse(y.toStringAsFixed(2));
var long4 = (long3 / 10000);
int decimals = 1;
int fac = pow(10, decimals);
double d = long4;
d = (d * fac).round() / fac;
print("d: $d");
getDistanceRun(_numerox);
setState(() {
_convert = d;
print(_convert);
});
}
void reset() {
setState(() {
int stepCountValue1 = 0;
stepCountValue1 = 0;
stepCountValue = "$stepCountValue1";
});
}
void _onDone() {}
void _onError(error) {
print("Flutter Pedometer Error: $error");
}
//function to determine the distance run in kilometers using number of steps
void getDistanceRun(double _numerox) {
var distance = ((_numerox * 76) / 100000);
distance = num.parse(distance.toStringAsFixed(2)); //dos decimales
var distancekmx = distance * 34;
distancekmx = num.parse(distancekmx.toStringAsFixed(2));
//print(distance.runtimeType);
var coiny = ((_numerox * 125) / 100000);
coiny = num.parse(coiny.toStringAsFixed(2));
setState(() {
_km = "$distance";
//print(_km);
});
setState(() {
_kmx = num.parse(distancekmx.toStringAsFixed(2));
});
setState(() {
_coin = num.parse(coiny.toStringAsFixed(2));
//print(_coiny);
});
}
//function to determine the calories burned in kilometers using number of steps
void getBurnedRun() {
setState(() {
var calories = _kmx; //dos decimales
_calories = "$calories";
//print(_calories);
});
}
void coins() {
setState(() {
var showcoin = _coin;
_showcoin = "$showcoin";
});
}
//fin codigo pedometer
@override
Widget build(BuildContext context) {
//print(_stepCountValue);
getBurnedRun();
coins();
return StreamProvider<List<Brew>>.value(
value: DatabaseService().step,
child: MaterialApp(
debugShowCheckedModeBanner: false,
home: new Scaffold(
appBar: new AppBar(
title: const Text('Step Counter'),
backgroundColor: Colors.black54,
actions: <Widget>[
FlatButton.icon(
icon: Icon(Icons.person),
label: Text('logout'),
onPressed: () async {
await _auth.signOut();
}
),
FlatButton.icon(
icon: Icon(Icons.arrow_back),
label: Text('New Page'),
onPressed: () {
Navigator.of(context)
.push(MaterialPageRoute(builder: (context) => pages()));
}
),
],
),
body: new ListView(
padding: EdgeInsets.all(5.0),
children: <Widget>[
Container(
padding: EdgeInsets.only(top: 10.0),
width: 250,
//ancho
height: 250,
//largo tambien por numero height: 300
decoration: BoxDecoration(
gradient: LinearGradient(
begin: Alignment
.bottomCenter, //cambia la iluminacion del degradado
end: Alignment.topCenter,
colors: [Color(0xFFA9F5F2), Color(0xFF01DFD7)],
),
borderRadius: BorderRadius.only(
bottomLeft: Radius.circular(27.0),
bottomRight: Radius.circular(27.0),
topLeft: Radius.circular(27.0),
topRight: Radius.circular(27.0),
)),
child: new CircularPercentIndicator(
radius: 200.0,
lineWidth: 13.0,
animation: true,
center: Container(
child: new Row(
crossAxisAlignment: CrossAxisAlignment.center,
children: <Widget>[
Container(
height: 50,
width: 50,
padding: EdgeInsets.only(left: 20.0),
child: Icon(
FontAwesomeIcons.walking,
size: 30.0,
color: Colors.white,
),
),
Container(
//color: Colors.orange,
child: Text(
'$stepCountValue',
style: TextStyle(
fontWeight: FontWeight.bold,
fontSize: 20.0,
color: Colors.purpleAccent),
),
// height: 50.0,
// width: 50.0,
),
],
),
),
percent: 0.217,
//percent: _convert,
footer: new Text(
"Steps: $stepCountValue",
style: new TextStyle(
fontWeight: FontWeight.bold,
fontSize: 12.0,
color: Colors.purple),
),
circularStrokeCap: CircularStrokeCap.round,
progressColor: Colors.purpleAccent,
),
),
Divider(
height: 5.0,
),
Container(
width: 80,
height: 100,
padding: EdgeInsets.only(left: 25.0, top: 10.0, bottom: 10.0),
color: Colors.transparent,
child: Row(
children: <Widget>[
new Container(
child: new Card(
child: Container(
height: 80.0,
width: 80.0,
decoration: BoxDecoration(
image: DecorationImage(
image: AssetImage("assets/images/distance.png"),
fit: BoxFit.fitWidth,
alignment: Alignment.topCenter,
),
),
child: Text(
"$_km Km",
textAlign: TextAlign.right,
style: new TextStyle(
fontWeight: FontWeight.bold, fontSize: 14.0),
),
),
color: Colors.white54,
),
),
VerticalDivider(
width: 20.0,
),
new Container(
child: new Card(
child: Container(
height: 80.0,
width: 80.0,
decoration: BoxDecoration(
image: DecorationImage(
image: AssetImage("assets/images/burned.png"),
fit: BoxFit.fitWidth,
alignment: Alignment.topCenter,
),
),
),
color: Colors.transparent,
),
),
VerticalDivider(
width: 20.0,
),
new Container(
child: new Card(
child: Container(
height: 80.0,
width: 80.0,
decoration: BoxDecoration(
image: DecorationImage(
image: AssetImage("assets/images/step.png"),
fit: BoxFit.fitWidth,
alignment: Alignment.topCenter,
),
),
),
color: Colors.transparent,
),
),
],
),
),
Divider(
height: 2,
),
Container(
padding: EdgeInsets.only(top: 2.0),
width: 150,
//ancho
height: 30,
//largo tambien por numero height: 300
color: Colors.transparent,
child: Row(
children: <Widget>[
new Container(
padding: EdgeInsets.only(left: 40.0),
child: new Card(
child: Container(
child: Text(
"$_km Km",
textAlign: TextAlign.right,
style: new TextStyle(
fontWeight: FontWeight.bold,
fontSize: 14.0,
color: Colors.white),
),
),
color: Colors.purple,
),
),
VerticalDivider(
width: 20.0,
),
new Container(
padding: EdgeInsets.only(left: 10.0),
child: new Card(
child: Container(
child: Text(
"$_calories kCal",
textAlign: TextAlign.right,
style: new TextStyle(
fontWeight: FontWeight.bold,
fontSize: 14.0,
color: Colors.white),
),
),
color: Colors.red,
),
),
VerticalDivider(
width: 5.0,
),
new Container(
padding: EdgeInsets.only(left: 10.0),
child: new Card(
child: Container(
child: Text(
"$_showcoin Coins",
textAlign: TextAlign.right,
style: new TextStyle(
fontWeight: FontWeight.bold,
fontSize: 14.0,
color: Colors.white),
),
),
color: Colors.black,
),
),
],
),
),
],
),
),
),
);
}
}
这是我的 wrapper.dart
import 'package:flutter_testing/models/user.dart';
import 'package:flutter_testing/screens/authenticate/authenticate.dart';
import 'package:flutter/material.dart';
import 'package:flutter_testing/main.dart';
import 'package:provider/provider.dart';
class Wrapper extends StatelessWidget {
@override
Widget build(BuildContext context) {
final user = Provider.of<User>(context);
// return either the Home or Authenticate widget
if (user == null){
return Authenticate();
} else {
return MyApp();
}
}
}
这是 page.dart
import 'package:flutter/material.dart';
import 'package:flutter_testing/main.dart';
import 'brew_list.dart';
class pages extends StatefulWidget {
@override
_pagesState createState() => _pagesState();
}
class _pagesState extends State<pages> {
@override
Widget build(BuildContext context) {
return Scaffold(
backgroundColor: Colors.amber,
appBar: new AppBar(
actions: <Widget>[
FlatButton.icon(
icon: Icon(Icons.arrow_back_ios),
label: Text('back'), onPressed: () {
Navigator.of(context)
.push(MaterialPageRoute(builder: (context) => MyApp())
);
}
),
],
),
body: BrewList(),
);
}
}
这是database.dart
import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:flutter_testing/models/brew.dart';
class DatabaseService {
final String uid;
DatabaseService({ this.uid });
// collection reference
final CollectionReference brewCollection = Firestore.instance.collection('step');
Future<void> updateUserData(int stepCountValue, int _calories, int _km , int _showcoin) async {
return await brewCollection.document(uid).setData({
'stepCountValue': stepCountValue,
'_calories': _calories,
'_km': _km,
'_showcoin': _showcoin,
});
}
// brew list from snapshot
List<Brew> _brewListFromSnapshot(QuerySnapshot snapshot) {
return snapshot.documents.map((doc){
return Brew(
stepCountValue: doc.data['stepCountValue'] ?? 0,
);
}).toList();
}
// get brews stream
Stream<List<Brew>> get step {
return brewCollection.snapshots()
.map(_brewListFromSnapshot);
}
}
这是 brew_list.dart
import 'package:flutter_testing/models/brew.dart';
import 'package:flutter/material.dart';
import 'package:provider/provider.dart';
import 'brew_tile.dart';
class BrewList extends StatefulWidget {
@override
_BrewListState createState() => _BrewListState();
}
class _BrewListState extends State<BrewList> {
@override
Widget build(BuildContext context) {
final step = Provider.of<List<Brew>>(context);
return ListView.builder(
itemCount: step.length,
itemBuilder: (context, index) {
return BrewTile(brew: step[index]);
},
);
}
}
这是 brew_tile.dart
import 'package:flutter_testing/models/brew.dart';
import 'package:flutter/material.dart';
class BrewTile extends StatelessWidget {
final Brew brew;
BrewTile({ this.brew });
@override
Widget build(BuildContext context) {
return Padding(
padding: const EdgeInsets.only(top: 8.0),
child: Card(
margin: EdgeInsets.fromLTRB(20.0, 6.0, 20.0, 0.0),
child: ListTile(
leading: CircleAvatar(
radius: 25.0,
backgroundColor: Colors.brown[brew.stepCountValue],
),
),
),
);
}
}
这是 brew.dart
class Brew {
final int stepCountValue;
Brew({ this.stepCountValue });
}
这是 pubspec.yaml
name: flutter_testing
description: A new Flutter application.
publish_to: 'none'
version: 1.0.0+1
environment:
sdk: ">=2.7.0 <3.0.0"
dependencies:
flutter:
sdk: flutter
# The following adds the Cupertino Icons font to your application.
# Use with the CupertinoIcons class for iOS style icons.
cupertino_icons: ^0.1.3
font_awesome_flutter: ^8.4.0
decimal: ^0.3.3
image_picker_saver: ^0.3.0
pedometer: ^0.0.5
percent_indicator: ^1.0.14
flutter_launcher_icons: ^0.7.0
firebase_auth: ^0.16.0
cloud_firestore: ^0.13.5
provider: ^4.2.2+2
flutter_spinkit: ^4.0.0
dev_dependencies:
flutter_test:
sdk: flutter
flutter_icons:
android: "launcher_icon"
ios: true
image_path: "assets/icon/step.png"
flutter:
# The following line ensures that the Material Icons font is
# included with your application, so that you can use the icons in
# the material Icons class.
uses-material-design: true
assets:
- assets/images/
我希望这足以解决我的问题。我对 Flutter 很陌生，所以如果你能说出我必须在哪里改变什么，那就太好了。太感谢了！！！
解决方案
您应该像这样公开 brew 列表：
class NewApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MultiProvider(
providers: [
StreamProvider<User>.value(value: AuthService().user),
StreamProvider<List<Brew>>.value(value: DatabaseService().step),
],
child: MaterialApp(
home: Wrapper(),
),
);
}
}
打电话之前：
final step = Provider.of<List<Brew>>(context);
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