检索数据currentuser.从firebase返回null [英] retrieve data currentuser. from firebase return null

问题描述

您好，我正在尝试从实时Firebase字段检索数据，但它返回null.我检查了textView52.setText(firebaseUser.getEmail());看看它是否真的连接并且可以正常工作.问题是从数据库中恢复一个值，在这种情况下，字段名称"可以有人帮助我吗? 难道我做错了什么? 欢迎任何帮助.

Hello I'm trying to retrieve the data from a realtime firebase field but it returns null. I checked with textView52.setText (firebaseUser.getEmail ()); to see if it was really connected and it works. the problem is in recovering a value from the database which in this case is the field "name" could someone help me? am i doing something wrong? any help is welcome.

    DatabaseReference ref = FirebaseDatabase.getInstance().getReference("Users");
    ref.child("Users").addListenerForSingleValueEvent(new ValueEventListener() {
        FirebaseUser user = FirebaseAuth.getInstance().getCurrentUser();
        String userUid = user.getUid();
        @Override
        public void onDataChange(DataSnapshot dataSnapshot) {
            String data = dataSnapshot.child("name").getValue(String.class);
            textView52.setText(data);
        }

        @Override
        public void onCancelled(@NonNull DatabaseError databaseError) {

        }
    });

}

推荐答案

尝试

FirebaseUser user = FirebaseAuth.getInstance().getCurrentUser();
String userUid = user.getUid();
DatabaseReference ref = FirebaseDatabase.getInstance().getReference();
ref.child("Users").child(userUid).addListenerForSingleValueEvent(new ValueEventListener() {

    @Override
    public void onDataChange(DataSnapshot dataSnapshot) {
        String data = dataSnapshot.child("name").getValue();
        textView52.setText(data);
    }

    @Override
    public void onCancelled(@NonNull DatabaseError databaseError) {

    }
});}

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