当我尝试在 listview.buider 中使用 snapshot.data.docs.length 时出现此错误：getter 'docs' 没有为类型 'Object' 定义

Question

I am trying to fetch data from firebase to list all the documents in a listview builder the code is still not completed in term of displaying the database filed in the code. this is the error: The getter 'docs' isn't defined for the type 'Object'

Container(
              child: StreamBuilder<Object>(
                  stream: _firestore
                      .collection('Patient')
                      .doc(_auth.currentUser.email)
                      .collection("Diabetes")
                      .snapshots(),
                  builder: (context, snapshot) {
                    if (snapshot.hasData) {
                      return ListView.builder(
                          reverse: true,
                          shrinkWrap: true,
                          itemCount:
                              snapshot.data.docs.length, // here is the error "docs"
                          itemBuilder: (context, index) {
                            DocumentSnapshot documentSnapshot =
                                snapshot.data.docs[index]; // also another error "docs"
                            return Container();
                          });
                    }
                    return Center(
                      child: CircularProgressIndicator(),
                    );
                  }),
            )

Answer 1

You should replace snapshot.data.docs.length with snapshot.data.length

 Container(
    child: StreamBuilder<Object>(
       stream: _firestore
         .collection('Patient')
         .doc(_auth.currentUser.email)
         .collection("Diabetes")
         .snapshots(),
       builder: (context, snapshot) {
         if (snapshot.hasData) {
           return ListView.builder(
               reverse: true,
               shrinkWrap: true,
               itemCount: snapshot.data.length,
               itemBuilder: (context, index) {
                 DocumentSnapshot documentSnapshot = snapshot.data[index];
                 return Container();
               });
        }
        return Center(
         child: CircularProgressIndicator(),
        );
     }),
    )

Answer 2

I solved the problem by replacing StreamBuilder<Object> with StreamBuilder<QuerySnapshot> . by default the StreamBuilder comes in this form StreamBuilder<Object>