how to retrieve single field data of type number from firebase in text widget flutter-CodePudding

I just want to retrieve a field from firebase firestore document which is <String, dynamic>, please tell me whats wrong with the code.

StreamBuilder(
          stream: FirebaseFirestore.instance
              .collection('qazanamazcalc')
              .snapshots(),
          builder: (ctx, AsyncSnapshot snap) {
            return Text(
              snap.data.docs['countcalc'],
              // snapshot.data['countcalc'],
            );
          },
        ),

I am getting these two errors 'docs' method not found Receiver: null Arguments: [] and Expected a value of type 'int', but got one of type 'String'

CodePudding user response：

First of all, are you using a stream, which is a continuous data stream that listens to changes in a collection or a specific document. If I understand your question correctly you just want to do one fetch on a specific document.

FutureBuilder<DocumentSnapshot<Map<String, dynamic>>>(
  future: FirebaseFirestore.instance.collection('qazanamazcalc').doc('doc_id').get(),
  builder: (_, snapshot) {    
    if (snapshot.hasData) {
      var data = snapshot.data!.data();
      var value = data!['countcalc'];
      return Text(value);
    }

    return Center(child: CircularProgressIndicator());
  },
)