how do I pass a value to another class?

Question

I have a variable 'phoneUser' that I want to pass to another class. Both classes are inherited from StatefulWidget. Passing through constructor does not work, the variable in the other class is empty.

void signInWithCredential(String smsCode) async {
    final AuthCredential credential = PhoneAuthProvider.getCredential(
      verificationId: _verificationId,
      smsCode: _smsController.text,);
    final FirebaseUser user = await _auth.signInWithCredential(credential);
    final FirebaseUser currentUser = await _auth.currentUser();
    final String phoneUser = currentUser.phoneNumber;// I wanna pass phoneUser to another class 

    setState(() {/.../}});
class Approval extends StatefulWidget {
  final String timePicked;
  final DateTime pickedDay;
  final String userPhone;
  Approval({Key key, @required DateTime picked, @required String timePicked,
    @required String phoneNumber})
      : pickedDay = picked, timePicked = timePicked, userPhone = phoneNumber,
        super(key: key);
  _ApprovalState createState() => new _ApprovalState(pickedDay,timePicked,userPhone);
}
class _ApprovalState extends State<Approval> {
  DatabaseReference itemRef = FirebaseDatabase.instance.reference().child('customers');
  final DateTime pickedDay;
  final String timePicked;
  final String userPhone;
  _ApprovalState(this.pickedDay, this.timePicked, this.userPhone);
////userPhone is empty here
/// This constructor also does not work:
class Amenities extends StatefulWidget {
  final String phoneNumber;
  Amenities({Key key, this.phoneNumber}):super(key: key);
  AmenitiesState createState() => new AmenitiesState();
}
Text(widget.phoneNumber) //phoneNumber is still empty

passing through constructor **does** work - post your class code and how you pass the values — pskink, Jun 09 '19 at 09:15
You should try passing value through function call from one class to another. — rajuugupta, Jun 09 '19 at 09:31
"You should try passing value through function call from one class to another." I dont know how pass method to another class and how i extract variable from method — Василий Гринько, Jun 09 '19 at 10:07
I did everything as in the post above, but I get an error "A non-null String must be provided to a Text widget". And in the class from which I want to get a variable, this variable is not used. How does this class understand that it should pass this variable to another class? — Василий Гринько, Jun 09 '19 at 10:30
Especially in the post says about passing data to a Stateful Widget. I have a different situation. — Василий Гринько, Jun 09 '19 at 10:33

score 0 · Answer 1 · answered Aug 28 '23 at 18:26

Passing a value to a class can be done using constructors.

The reason why you're getting the error "A non-null String must be provided to a Text widget" is because you're passing a nullable value. Adding a null-check or defining a default value should solve this issue.

how do I pass a value to another class?

1 Answers1