Firebase会返回重复值

Question

我试图从我的Firebase数据库中获取posts和uid。我用这个：

mPostReference = FirebaseDatabase.getInstance().getReference()
            .child("posts");
mPostReference.addListenerForSingleValueEvent(
        new ValueEventListener() {
            @Override
            public void onDataChange(DataSnapshot dataSnapshot) {
               // Get Post object and use the values to update the UI

                for (DataSnapshot postSnapshot: dataSnapshot.getChildren()) {
                    String uid = (String) postSnapshot.child("uid").getValue();
                    String body = (String) postSnapshot.child("body").getValue();
                    Long num = dataSnapshot.getChildrenCount();
                    Toast.makeText(getActivity(), body, Toast.LENGTH_SHORT).show();
                    Toast.makeText(getActivity(), num.toString(),  Toast.LENGTH_SHORT).show();


                }
            }

我将num值设为3，但我获得的数据是重复的。相同的body＆amp; uid一次又一次地被提取。如何在一次迭代中停止？

Answer 1

Long num = dataSnapshot.getChildrenCount();

将此行代码移到for循环外。