DatabaseReference myRef = database.getReference("message");
myRef.addListenerForSingleValueEvent(
new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
//Get map of users in datasnapshot
collectPhoneNumbers((Map<String,Object>) dataSnapshot.getValue());
}
@Override
public void onCancelled(DatabaseError databaseError) {
//handle databaseError
}
});
private void collectPhoneNumbers(Map<String,Object> users)
{
ArrayList<String> phoneNumbers = new ArrayList<>();
List<ItemObjectVideo> allItems = new ArrayList<ItemObjectVideo>();
//iterate through each user, ignoring their UID
for (Map.Entry<String, Object> entry : users.entrySet()){
//Get user map
Map singleUser = (Map) entry.getValue();
//Get phone field and append to list
phoneNumbers.add((String)singleUser.get("url"));
allItems.add(new ItemObjectVideo((String)singleUser.get("name")));
}
rcAdapter = new VideoRecyclerViewAdapter(getApplicationContext(), allItems);
rView.setAdapter(rcAdapter);
rcAdapter.notifyDataSetChanged();
}
我建議檢查出的[文件](https://firebase.google.com/docs/database/android/lists-of-data#child-events)或嘗試[代碼實驗室(https://開頭codelabs .developers.google.com/codelabs /火力-機器人/)。 –