FutureBuilder doesn't work properly with Firestore - flutter

Question

can't create a query using FutureBuilder.
Firestore is at the latest version.
This is the case for both Android and iOS devices, any ideas?
return FutureBuilder<QuerySnapshot>(
future: Firestore.instance
.collection('productlist')
.where('productid', isEqualTo: pid)
.limit(
1), // a previously-obtained Future<String> or null
builder: (BuildContext context,
AsyncSnapshot<QuerySnapshot> snapshot) {
if (snapshot.hasData) {
productname = snapshot.data.documents[0]['productname'];
print("productname:" + productname);
}
else{
productname = "0";
}
},
);

Answer 1

I think the issue here is that you are not returning a widget.
Try the code below
FutureBuilder(
future: Firestore.instance
.collection('productlist')
.where('productid', isEqualTo: pid)
.limit(1),
builder: (ctx, snapshot) {
if (snapshot.connectionState == ConnectionState.done && snapshot.hasData) {
return Text(snapshot.data.documents[0]['productname']);
} else {
return Text("0");
}
},
),

Answer 2

u can use stream builder instead it works pretty well :
return StreamBuilder<QuerySnapshot>(
stream: Firestore.instance.collection('productlist').where('productid', isEqualTo: pid).limit(1),
builder: (context, snapshot) {
if (snapshot.data != null) {
// Here u will get list of document snapshots
final List<DocumentSnapshot> documents = snapshot.data.documents;
// now u can access each document by simply specifying its number
// u can also use list view to display every one of them
return ListView.builder(
itemCount: documents.length,
itemBuilder: (context, int index) => Text(documents[index]['productname']),
);
} else {
// Show loading indicator here
}
},
);