How to get rid of the exception initial value was called on null
Question
Hi i am trying to fetch the images from firebase then returning it in a Carousel slider.builder but whenever app loads it throws the following exception. The images are stored in Firebase. I could not figure out why its not fetching the detials. The attributes are correct but still its not fetching the image from firebase.
I/flutter (13636): ══╡ EXCEPTION CAUGHT BY WIDGETS LIBRARY ╞═══════════════════════════════════════════════════════════
I/flutter (13636): The following NoSuchMethodError was thrown building FutureBuilder<dynamic>(state:
I/flutter (13636): _FutureBuilderState<dynamic>#eb8ff):
I/flutter (13636): The getter 'initialPage' was called on null.
I/flutter (13636): Receiver: null
I/flutter (13636): Tried calling: initialPage
I/flutter (13636):
I/flutter (13636): The relevant error-causing widget was:
I/flutter (13636): FutureBuilder<dynamic>
I/flutter (13636): file:///C:/Users/pranjal.kumar.deb/AndroidStudioProjects/home_page/lib/main.dart:79:19
I/flutter (13636): "
This is my code
import 'package:flutter/material.dart';
import 'package:carousel_pro/carousel_pro.dart';
import 'package:curved_navigation_bar/curved_navigation_bar.dart';
import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:home_page/Allitem_Screen.dart';
import 'package:carousel_slider/carousel_controller.dart';
import 'package:carousel_slider/carousel_options.dart';
import 'package:carousel_slider/carousel_slider.dart';
void main() {
runApp(MyApp());
}
class MyApp extends StatefulWidget {
@override
_MyAppState createState() => _MyAppState();
}
class _MyAppState extends State<MyApp> {
@override
Widget build(BuildContext context) {
////Image Carousel Widget////
Future getImageFromFirebase() async {
var firestore = Firestore.instance;
QuerySnapshot qn = await firestore.collection("AllimageSlider").getDocuments();
return qn.documents;
}
////Widget Carousel/////
return MaterialApp(
debugShowCheckedModeBanner: false,
home: SafeArea(
child: Scaffold(
appBar: AppBar(backgroundColor: Colors.red.withGreen(10),
title: Padding(
padding: const EdgeInsets.all(1),
child: Text('SDE',style: TextStyle(color: Colors.white),
),
),
titleSpacing: 50.0,
),
body: SingleChildScrollView(
scrollDirection: Axis.vertical,
child: Container(
height: 1350,
color: Colors.white,
child: Column(
children: <Widget>[
FutureBuilder(
future: getImageFromFirebase(),
builder: (context,snapshot){
if (snapshot.hasData){
return CarouselSlider.builder(
itemCount: snapshot.data.length,
itemBuilder: (context,index){
DocumentSnapshot doc = snapshot.data[index];
return Container(
child: Image.network(doc['imageUrl']),
);
},
);
}
return Text('Loading');
},
),
//// image carousel Widget
Padding(
padding: const EdgeInsets.fromLTRB(0,20,0,0),
child: Container(child: Text('Sugar, Jaggery & Salt',style: TextStyle(fontSize: 20.0,fontWeight: FontWeight.bold),), alignment: Alignment.bottomLeft,
),
),
Container(
height: 150,
child: StreamBuilder(
stream: Firestore.instance.collection('SugarJaggerySalt').snapshots(),
builder: (BuildContext context, AsyncSnapshot<QuerySnapshot> snapshot){
if (snapshot.hasData){
return ListView.builder(
scrollDirection: Axis.horizontal,
itemCount: snapshot.data.documents.length,
itemBuilder: (context, index){
DocumentSnapshot rawItems = snapshot.data.documents[index];
return Container(
width: 160.0,
child: InkWell(
onTap: (){
print('Kak Babu'+index.toString());
print(rawItems["UID"]);
Navigator.push(context, MaterialPageRoute(builder: (context)=>AllItemScreen(itemName:rawItems["UID"],)));
},
child: Card(
child: Wrap(
children: <Widget>[
Container(
margin: EdgeInsets.all(10.0),
child: Image.network(rawItems["image"],
height: 80,
width: 160,
),
),
ListTile(
title: Row(
mainAxisAlignment: MainAxisAlignment
.spaceEvenly,
children: <Widget>[
Text(rawItems["UID"],
textAlign: TextAlign.center,),
],
),
)
],
),
),
),
);
}
);
}
else{
return Center(
child: Container(),
);
}
}
),
),
Padding(
padding: const EdgeInsets.fromLTRB(0,20,0,0),
child: Container(child: Text('Sugar, Jaggery & Salt',style: TextStyle(fontSize: 20.0,fontWeight: FontWeight.bold),), alignment: Alignment.bottomLeft,
),
),
Container(
height: 150,
child: StreamBuilder(
stream: Firestore.instance.collection('SugarJaggerySalt').snapshots(),
builder: (BuildContext context, AsyncSnapshot<QuerySnapshot> snapshot){
if (snapshot.hasData){
return ListView.builder(
scrollDirection: Axis.horizontal,
itemCount: snapshot.data.documents.length,
itemBuilder: (context, index){
DocumentSnapshot rawItems = snapshot.data.documents[index];
return Container(
width: 160.0,
child: InkWell(
onTap: (){
print('Kak Babu'+index.toString());
print(rawItems["UID"]);
Navigator.push(context, MaterialPageRoute(builder: (context)=>AllItemScreen(itemName:rawItems["UID"],)));
},
child: Card(
child: Wrap(
children: <Widget>[
Container(
margin: EdgeInsets.all(10.0),
child: Image.network(rawItems["image"],
height: 80,
width: 160,
),
),
ListTile(
title: Row(
mainAxisAlignment: MainAxisAlignment
.spaceEvenly,
children: <Widget>[
Text(rawItems["UID"],
textAlign: TextAlign.center,),
],
),
)
],
),
),
),
);
}
);
}
else{
return Center(
child: Container(),
);
}
}
),
),
////Category 1 widget
//// Category 2 Widget
//// Category 3
],
),
),
),
),
),
);
}
}
1 answers
solution1
0 2020-08-16 09:23:51
Hi i am trying to fetch the images from firebase then returning it in a Carousel slider.builder but whenever app loads it throws the following exception. The images are stored in Firebase. I could not figure out why its not fetching the detials. The attributes are correct but still its not fetching the image from firebase.
I/flutter (13636): ══╡ EXCEPTION CAUGHT BY WIDGETS LIBRARY ╞═══════════════════════════════════════════════════════════
I/flutter (13636): The following NoSuchMethodError was thrown building FutureBuilder<dynamic>(state:
I/flutter (13636): _FutureBuilderState<dynamic>#eb8ff):
I/flutter (13636): The getter 'initialPage' was called on null.
I/flutter (13636): Receiver: null
I/flutter (13636): Tried calling: initialPage
I/flutter (13636):
I/flutter (13636): The relevant error-causing widget was:
I/flutter (13636): FutureBuilder<dynamic>
I/flutter (13636): file:///C:/Users/pranjal.kumar.deb/AndroidStudioProjects/home_page/lib/main.dart:79:19
I/flutter (13636): "
This is my code
import 'package:flutter/material.dart';
import 'package:carousel_pro/carousel_pro.dart';
import 'package:curved_navigation_bar/curved_navigation_bar.dart';
import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:home_page/Allitem_Screen.dart';
import 'package:carousel_slider/carousel_controller.dart';
import 'package:carousel_slider/carousel_options.dart';
import 'package:carousel_slider/carousel_slider.dart';
void main() {
runApp(MyApp());
}
class MyApp extends StatefulWidget {
@override
_MyAppState createState() => _MyAppState();
}
class _MyAppState extends State<MyApp> {
@override
Widget build(BuildContext context) {
////Image Carousel Widget////
Future getImageFromFirebase() async {
var firestore = Firestore.instance;
QuerySnapshot qn = await firestore.collection("AllimageSlider").getDocuments();
return qn.documents;
}
////Widget Carousel/////
return MaterialApp(
debugShowCheckedModeBanner: false,
home: SafeArea(
child: Scaffold(
appBar: AppBar(backgroundColor: Colors.red.withGreen(10),
title: Padding(
padding: const EdgeInsets.all(1),
child: Text('SDE',style: TextStyle(color: Colors.white),
),
),
titleSpacing: 50.0,
),
body: SingleChildScrollView(
scrollDirection: Axis.vertical,
child: Container(
height: 1350,
color: Colors.white,
child: Column(
children: <Widget>[
FutureBuilder(
future: getImageFromFirebase(),
builder: (context,snapshot){
if (snapshot.hasData){
return CarouselSlider.builder(
itemCount: snapshot.data.length,
itemBuilder: (context,index){
DocumentSnapshot doc = snapshot.data[index];
return Container(
child: Image.network(doc['imageUrl']),
);
},
);
}
return Text('Loading');
},
),
//// image carousel Widget
Padding(
padding: const EdgeInsets.fromLTRB(0,20,0,0),
child: Container(child: Text('Sugar, Jaggery & Salt',style: TextStyle(fontSize: 20.0,fontWeight: FontWeight.bold),), alignment: Alignment.bottomLeft,
),
),
Container(
height: 150,
child: StreamBuilder(
stream: Firestore.instance.collection('SugarJaggerySalt').snapshots(),
builder: (BuildContext context, AsyncSnapshot<QuerySnapshot> snapshot){
if (snapshot.hasData){
return ListView.builder(
scrollDirection: Axis.horizontal,
itemCount: snapshot.data.documents.length,
itemBuilder: (context, index){
DocumentSnapshot rawItems = snapshot.data.documents[index];
return Container(
width: 160.0,
child: InkWell(
onTap: (){
print('Kak Babu'+index.toString());
print(rawItems["UID"]);
Navigator.push(context, MaterialPageRoute(builder: (context)=>AllItemScreen(itemName:rawItems["UID"],)));
},
child: Card(
child: Wrap(
children: <Widget>[
Container(
margin: EdgeInsets.all(10.0),
child: Image.network(rawItems["image"],
height: 80,
width: 160,
),
),
ListTile(
title: Row(
mainAxisAlignment: MainAxisAlignment
.spaceEvenly,
children: <Widget>[
Text(rawItems["UID"],
textAlign: TextAlign.center,),
],
),
)
],
),
),
),
);
}
);
}
else{
return Center(
child: Container(),
);
}
}
),
),
Padding(
padding: const EdgeInsets.fromLTRB(0,20,0,0),
child: Container(child: Text('Sugar, Jaggery & Salt',style: TextStyle(fontSize: 20.0,fontWeight: FontWeight.bold),), alignment: Alignment.bottomLeft,
),
),
Container(
height: 150,
child: StreamBuilder(
stream: Firestore.instance.collection('SugarJaggerySalt').snapshots(),
builder: (BuildContext context, AsyncSnapshot<QuerySnapshot> snapshot){
if (snapshot.hasData){
return ListView.builder(
scrollDirection: Axis.horizontal,
itemCount: snapshot.data.documents.length,
itemBuilder: (context, index){
DocumentSnapshot rawItems = snapshot.data.documents[index];
return Container(
width: 160.0,
child: InkWell(
onTap: (){
print('Kak Babu'+index.toString());
print(rawItems["UID"]);
Navigator.push(context, MaterialPageRoute(builder: (context)=>AllItemScreen(itemName:rawItems["UID"],)));
},
child: Card(
child: Wrap(
children: <Widget>[
Container(
margin: EdgeInsets.all(10.0),
child: Image.network(rawItems["image"],
height: 80,
width: 160,
),
),
ListTile(
title: Row(
mainAxisAlignment: MainAxisAlignment
.spaceEvenly,
children: <Widget>[
Text(rawItems["UID"],
textAlign: TextAlign.center,),
],
),
)
],
),
),
),
);
}
);
}
else{
return Center(
child: Container(),
);
}
}
),
),
////Category 1 widget
//// Category 2 Widget
//// Category 3
],
),
),
),
),
),
);
}
}
solution2
0 2020-08-16 11:38:17
I figured out there is property called option in the image carousel slider it was null that was the reason for the error
options: CarouselOptions( height: 400, aspectRatio: 16/9, viewportFraction: 0.8, initialPage: 0, enableInfiniteScroll: true, reverse: false, autoPlay: true, autoPlayInterval: Duration(seconds: 3), autoPlayAnimationDuration: Duration(milliseconds: 800), autoPlayCurve: Curves.fastOutSlowIn, enlargeCenterPage: true,
scrollDirection: Axis.horizontal,
),
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