Useful or not, from you.
flutter type 'List<Widget>' is not a subtype of type 'Widget'

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Error: type 'List<Widget>' is not a subtype of type 'Widget'

generateStudentList(AsyncSnapshot<QuerySnapshot> snapshot) { return snapshot.data.documents .map<Widget>( (doc) => new ListTile( title: new Text(doc['name']), subtitle: Text( doc['age'].toString(), ), trailing: Container( width: 100, child: Row( children: <Widget>[ IconButton( onPressed: () { setState(() { _nameController.text = doc['name']; _ageController.text = doc['age'].toString(); docIdToUpdate = doc.documentID; isUpdate = true; }); }, icon: Icon( Icons.edit, color: Colors.blue, ), ), IconButton( onPressed: () { deleteStudent(doc); }, icon: Icon( Icons.delete, color: Colors.red, ), ), ], ), ), )) .toList(); }