Android 使用addValueEventListener（）时，Firebase数据库权限被拒绝错误

我正在使用Firebase获取数据并将其加载到片段中。该片段包含一个列表，我想在其中使用适配器添加日期。适配器接受3个ArrayList作为输入，以创建自定义列表

以下是

AttendanceFragment

：

public class AttendanceFragment extends Fragment {

    private DatabaseReference reference, attendance, classid, divisionid, studentid, dates;
    private Button attbutton;
    private ListView list;
    private View mainview;
    private Activity activity;
    private ArrayList<String> date = new ArrayList<String>(),
            state = new ArrayList<String>(),
            teacher = new ArrayList<String>();
    private ListAdapter listAdapter;

    @Nullable
    @Override
    public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        return inflater.inflate(R.layout.fragment_attendence,container,false);
    }

    @Override
    public void onStart(){
        super.onStart();

        mainview = this.getView();
        activity = this.getActivity();
        attbutton = mainview.findViewById(R.id.att_per);
        list = mainview.findViewById(R.id.att_main_list);

        reference = FirebaseDatabase.getInstance().getReference();
        attendance = reference.child(KeyStrings.attendance);
        classid = attendance.child(KeyStrings.class1);
        divisionid = classid.child(KeyStrings.division1);
        studentid = divisionid.child(KeyStrings.student1);
        dates = studentid.child("2018-07-06");
        attbutton.setText(dates.getKey());

        studentid.addValueEventListener(new ValueEventListener() {
            @Override
            public void onDataChange(DataSnapshot dataSnapshot) {
                Toast.makeText(activity, "Does it work?", Toast.LENGTH_LONG).show();
                for(DataSnapshot d1: dataSnapshot.getChildren()){
                    date.add(d1.getKey());
                    state.add(d1.child(KeyStrings.att_status).getValue().toString());
                    teacher.add(d1.child(KeyStrings.att_created_by).getValue().toString());
                }

                listAdapter = new AttendanceAdapter(activity, date, state, teacher);
                list.setAdapter(listAdapter);

            }

            @Override
            public void onCancelled(DatabaseError databaseError) {

            }
        });

    }

}

编辑1

正如我前面所说，Firebase可能没有权限或身份验证问题。但规则如下：

{ “规则”：{ “.read”：正确， “.write”：正确 }

---

}

请在问题中包括您的数据结构和安全规则。您能与我们分享您的Firebase数据库安全规则吗？您可以从中访问规则。

public class AttendanceAdapter extends ArrayAdapter<String>{
    private ArrayList<String> date;
    private ArrayList<String> state;
    private ArrayList<String> teacher;
    private Activity context;

    public AttendanceAdapter(Activity context, ArrayList<String>date, ArrayList<String>state, ArrayList<String>teacher) {
        super(context, R.layout.fragment_attendence, date);
        this.date=date;
        this.state=state;
        this.teacher=teacher;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent){
        LayoutInflater inflater = context.getLayoutInflater();
        View listviewItem = inflater.inflate(R.layout.fragment_attendence,null,true);
        TextView dateview=(TextView)listviewItem.findViewById(R.id.att_list_date);
        TextView stateview=(TextView)listviewItem.findViewById(R.id.att_list_stat);
        TextView teacherview=(TextView)listviewItem.findViewById(R.id.att_list_teacher);

        dateview.setText(date.get(position));
        stateview.setText(state.get(position));
        teacherview.setText(teacher.get(position));
        return listviewItem;
    }
}