在android firebase中获取父节点

Question

这是我目前的代码。如何获取名字的父节点

final Query userQuery = mRef.orderByChild("First Name");

    userQuery.addChildEventListener(new ChildEventListener() {
        @Override
        public void onChildAdded(DataSnapshot dataSnapshot, String s) {
            map.clear();
            for (DataSnapshot child: dataSnapshot.getChildren())
            {
                String key = child.getKey().toString();
                String value = child.getValue().toString();
                map.put(key,value);
            }

Answer 1

您应该在检索到的getKey()中调用dataSnapshot方法：

  final Query userQuery = mRef.orderByChild("First Name");

  userQuery.addChildEventListener(new ChildEventListener() {
     @Override
     public void onChildAdded(DataSnapshot dataSnapshot, String s) {
        map.clear();
        //Get the node from the datasnapshot
        String myParentNode = dataSnapshot.getKey();
        for (DataSnapshot child: dataSnapshot.getChildren())
        {
           String key = child.getKey().toString();
           String value = child.getValue().toString();
           map.put(key,value);
        }