"The method 'cast' isn't defined for the type 'Object'" when reading from Firebase

Question

I create banner in listview and get the data from firebase database.

Future<List<String>> getBaners(DatabaseReference bannerRef){
  //The method 'cast' isn't defined for the type 'Object'.
  return bannerRef.once().then((snapshot) => snapshot.snapshot.value!.cast<String>().toList());
}

Answer 1

Try using

Future<List<String>> getBaners(DatabaseReference bannerRef)async{ 
  final DataSnapshot res = await bannerRef.get();
  if(res.exists)
    return res.value as List<String>;
  return [];
}
 

I am willing to help more if you can provide more details about the structure of the data that bannerRef is pointing to.