Class 'Future<DocumentSnapshot<Map<String, dynamic>>>' has no instance method '[]'

Question

I'm making the profile screen(for user to change his profile image). Whenever the profile image is changed, the user's profile url in the Firestore DB changes through Firesbase Storage. And i have to reflect this change, so I brought the user doc(in Firestore DB) to stream. And I want to use the value of the field 'profileurl' in the user doc, but it doesn't work with the error below. I entered coding for the first time with a flutter. Please excuse if the question is stupid.

The error is

" Class 'Future<DocumentSnapshot<Map<String, dynamic>>>' has no instance method '[]'. Receiver: Instance of 'Future<DocumentSnapshot<Map<String, dynamic>>>' Tried calling: "

Here is the firestore. widget pickImage (using Imagepicker package) is well working, so i didnt write a code in this qu

Here is my Code.

class Ppage5_on extends StatefulWidget {
  const Ppage5_on({Key? key}) : super(key: key);

  @override
  State<Ppage5_on> createState() => _Ppage5_onState();
}

class _Ppage5_onState extends State<Ppage5_on> {

  @override
  initState() {
    userData = FirebaseFirestore.instance 
        .collection('member')
        .doc(FirebaseAuth.instance.currentUser!.email!).get();
    super.initState();
  }

  var userData;
  var ProfileUrl = "";
  final userQuery = FirebaseFirestore.instance
      .collection('member')
      .where('email', isEqualTo: FirebaseAuth.instance.currentUser!.email!);

  Widget _buildBody(BuildContext context) {
    return StreamBuilder<QuerySnapshot> (
      stream: userQuery.snapshots(),
      builder: (context, snapshot) {
        ///I think the error is occuered on here 
        setState(() {
          ProfileUrl = userData['profileUrl'];
        });
        if (!snapshot.hasData) return LinearProgressIndicator();
        return Scaffold(
            child: Column(
              children: [
                    ProfileUrl == ""
                        ? Stack( ...)
                        : Stack(children: [
                            CircleAvatar(
                                radius: 50,
                                backgroundImage: NetworkImage(
                                    ProfileUrl) ...} //Widget _buildbody end

  @override
  Widget build(BuildContext context) {
    return Scaffold(

      body: _buildBody(context)
    );
  }
}

Answer 1

Change this line to look like this:

ProfileUrl = snapshot.data()?['profileUrl'];