how to get id sent with a Screen in flutter

Question

i send an idd from another screen when i want to navigate to this WaitingScreen

Now when i want to use the idd , I get an error in the line

FirebaseFirestore.instance.collection('ambulance').doc(idd).get()

class WaitingScreen extends StatefulWidget  {
  final String idd; 
  String? Key;

  WaitingScreen({required this.idd}) : super();

  _WaitingScreenState createState () => _WaitingScreenState(  ) ; 
}

class _WaitingScreenState extends State<WaitingScreen> with SingleTickerProviderStateMixin{

late AnimationController _controller;

@override
  void initState() {
    super.initState();
    _controller =
        AnimationController(vsync: this, duration: Duration(minutes: 5));
    _controller.forward();
  }

  @override
  Widget build(BuildContext context) {
    String? valuee;    

    return  FutureBuilder<DocumentSnapshot>( 
        future: FirebaseFirestore.instance.collection('ambulance').doc(idd).get(),

Answer 1

When using a stateful widget, you need to reference variables on the widget itself by using the following construction:

widget.idd

By using the prefix widget., you make sure to access the variables on the widget, and not on the state you are in.