问题
I am trying to fetch data from Friebase-firestore and then convert it to model, I used the same code and approach to another project (web project) ,it works fine , but with this project it doesn't work ,I don't know why. I upgrade flutter version, run Flutter doctor , and nothing wrong with the environment setup. here is the code :
class dbService{
static final CollectionReference myCollection =
FirebaseFirestore.instance.collection('myCollection');
static Future<myModel> getMyInfo() async{
myModel sanaa ;
print('this line to print');
final QuerySnapshot myInfo =await myCollection.limit(1).get();
myInfo.docs.forEach((element) {
print(element.data()['name']);
sanaa= new myModel(
name:element.data()['name'].toString(),
title: element.data()["title"].toString(),
img: element.data()['img'].toString(),
);
print('\n print ------ ');
print(element.data()['name']);
print(' that is');
}
);
return sanaa;
}
}
class dbManager{
Stream<myModel> myInfoStream() async*{
yield await dbService.getMyInfo();
}
}
class _aboutStateState extends State<aboutState> {
Stream stream ;
dbManager mng = new dbManager();
@override
void initState() {
// TODO: implement initState
stream = mng.myInfoStream();
super.initState();
}
@override
Widget build(BuildContext context) {
return Container(
color: Colors.pink[300],
child: StreamBuilder<myModel>(
stream: stream,
builder: (context, snapshot){
if(snapshot.hasError){
print(snapshot.error);
return Center(child: Text('Something went wrong , please try again later'),);
}
else if(snapshot.hasData){
return Text("${snapshot.data.name}");
}
else {
return Center(child: CircularProgressIndicator());
}
},
),
I got this error
this line to print
[cloud_firestore/unknown] NoSuchMethodError: invalid member on null: 'includeMetadataChanges'
but when I connect directly to the firestore without converting it into model ,It works fine and print the data in the screen , the code :
child:FutureBuilder(
future: me.doc(id).get(),
builder: (context, snapshot){
if(snapshot.hasError){
print(snapshot.error);
return Center(child: Text('Something went wrong , please try again later'),);
}
else if(snapshot.hasData){
// print("${snapshot.data.data()['app_pics'][1]} \n${snapshot.data.data()['img']}");
return Text("${snapshot.data.data()['app_pics'][1]}");
}
else {
return Center(child: CircularProgressIndicator());
}
},
),
I run flutter doctor
Doctor summary (to see all details, run flutter doctor -v):
[√] Flutter (Channel beta, 1.24.0-10.2.pre, on Microsoft Windows [Version 6.3.9600], locale
en-US)
[√] Android toolchain - develop for Android devices (Android SDK version 29.0.2)
[√] Chrome - develop for the web
[√] Android Studio (version 4.0)
[√] VS Code (version 1.51.0)
[√] Connected device (3 available)
• No issues found!
Please I need help
回答1:
I found the answer, it caused because of the version of Firebase JS SDK . I replace 8.1.1 to 7.22.1 in index.html file
<!-- The core Firebase JS SDK is always required and must be listed first -->
<!-- <script src="https://www.gstatic.com/firebasejs/8.1.1/firebase-app.js"></script>-->
<!-- <!– TODO: Add SDKs for Firebase products that you want to use-->
<!-- https://firebase.google.com/docs/web/setup#available-libraries –>- ->
<!-- <script src="https://www.gstatic.com/firebasejs/8.1.1/firebase-firestore.js">
</script>-->
<!-- <script src="https://www.gstatic.com/firebasejs/8.1.1/firebase-analytics.js"></script>-->
I am using 7.22.1 version for Firebase JS SDK
<script src="https://www.gstatic.com/firebasejs/7.22.1/firebase-app.js"></script>
<!-- TODO: Add SDKs for Firebase products that you want to use
https://firebase.google.com/docs/web/setup#available-libraries -->
<script src="https://www.gstatic.com/firebasejs/7.22.1/firebase-firestore.js"></script>
<script src="https://www.gstatic.com/firebasejs/7.22.1/firebase-analytics.js"></script>
回答2:
Try out this versions:
firebase_core: ^0.5.2
cloud_firestore: ^0.14.3
For more info check out this github Link
回答3:
You can also use 8.0.1 as mentioned here and subscribe to the issue. Then you get (hopefully) notified once it´s fixed.
https://github.com/FirebaseExtended/flutterfire/issues/4127#issuecomment-754171740
来源：https://stackoverflow.com/questions/65001207/flutter-cloud-firestore-unknown-nosuchmethoderror-invalid-member-on-null-i