java - 我有一个用户类，它有一个私有字段 ArrayList<object>, I wish to display all ArrayList<object> in a recycler view <div id="body"><p>I wish to retrieve my the elements inside Users that as a field of ArrayList and display each schedule object and its fields in a recyclervie

问题描述

I wish to retrieve my the elements inside Users that as a field of ArrayList and display each schedule object and its fields in a recyclerview.

I have used the model , adapter pattern that most people used but i do not know how to retrieve data for the "schedule" because it is nested.

I get an error saying recycler view no adpater attach.

I have tried doing this

public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {

    View view =inflater.inflate(R.layout.fragment_schedule,container,false);
    final ArrayList<ScheduleItem> schedulelist = new ArrayList<>();
    firebaseDatabase=firebaseDatabase.getInstance();
    myRef=firebaseDatabase.getReference("Users").child(userID);
    recyclerView= view.findViewById(R.id.my_recycler_view);
    recyclerView.setHasFixedSize(true);
    mLayoutman= new LinearLayoutManager(getActivity());
    madapter= new ScheduleAdapter(schedulelist);
    FirebaseUser user = firebaseAuth.getCurrentUser();
    userID = user.getUid();

    myRef.addValueEventListener(new ValueEventListener() {
        @Override
        public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
            for (DataSnapshot ds : dataSnapshot.getChildren()) {
                User user = new User();
                user = ds.getValue(User.class);

                ArrayList<ScheduleItem> scheduleItems = user.getSchedule();
                for (int i = 0; i < scheduleItems.size(); i++) {
                    Parent = scheduleItems.get(i).getParent_N();
                    Kid = scheduleItems.get(i).getKid_N();
                    Time = scheduleItems.get(i).getTime();
                    Date= scheduleItems.get(i).getDate();
                    Place= scheduleItems.get(i).getPlace();
                    schedulelist.add(new ScheduleItem(Parent, Kid, Time,Date,Place));
                    Log.d(TAG, "onDataChange: ");
                }
                recyclerView.setAdapter(madapter);
                recyclerView.setLayoutManager(mLayoutman);
            }
        }

        @Override
        public void onCancelled(@NonNull DatabaseError databaseError) {
            System.out.print("Failed");

        }
    });

    return view;

}

}

and here is my adapter

//formatted code
public class ScheduleAdapter extends RecyclerView.Adapter<ScheduleAdapter.ScheduleViewHolder> {
    private ArrayList<ScheduleItem> displaylist;

public static class ScheduleViewHolder extends RecyclerView.ViewHolder{
    private TextView Parent_name;
    private TextView Kid_name;
    private TextView Time;
    private TextView Date;
    private TextView Place;

    public ScheduleViewHolder(@NonNull View itemView) {
        super(itemView);
        Parent_name = itemView.findViewById(R.id.s_parent);
        Kid_name=itemView.findViewById(R.id.s_kid);
        Time=itemView.findViewById(R.id.s_time);
        Date=itemView.findViewById(R.id.s_date);
        Place=itemView.findViewById(R.id.s_place);
    }
}

public ScheduleAdapter(ArrayList<ScheduleItem> list) {
    this.displaylist=list;
}

@NonNull
@Override
public ScheduleViewHolder onCreateViewHolder(@NonNull ViewGroup viewGroup, int i) {
    View view= LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.schedule_item,viewGroup,false);
    ScheduleViewHolder x= new ScheduleViewHolder(view);
    return x;
}

@Override
public void onBindViewHolder(@NonNull ScheduleViewHolder scheduleViewHolder, int i) {
    ScheduleItem current=displaylist.get(i);
    scheduleViewHolder.Parent_name.setText(current.getParent_N());
    scheduleViewHolder.Kid_name.setText(current.getKid_N());
    scheduleViewHolder.Time.setText(current.getTime());
    scheduleViewHolder.Date.setText(current.getDate());
    scheduleViewHolder.Place.setText(current.getPlace());

}

@Override
public int getItemCount() {
    return displaylist.size();
}

}

here is my schedule model`

public class ScheduleItem {
private String Parent_N;
private String Kid_N;
private String Time;
private String Date;
private String Place;


public ScheduleItem(String parent_N, String kid_N, String time, String date, String place) {
    Parent_N = parent_N;
    Kid_N = kid_N;
    Time = time;
    Date = date;
    Place = place;
}

public String getParent_N() {
    return Parent_N;
}

public void setParent_N(String parent_N) {
    Parent_N = parent_N;
}

public String getKid_N() {
    return Kid_N;
}

public void setKid_N(String kid_N) {
    Kid_N = kid_N;
}

public String getTime() {
    return Time;
}

public void setTime(String time) {
    Time = time;
}

public String getDate() {
    return Date;
}

public void setDate(String date) {
    Date = date;
}

public String getPlace() {
    return Place;
}

public void setPlace(String place) {
    Place = place;
}

}

` and my user model

public class User {
private User userObject;
public String email, username, userType;
public ArrayList<ScheduleItem> schedule;

public User(){
}

public User(String email){
    this.email = email;

}

public User(String email, String username, String userType) {
    this.email = email;
    this.username = username;
    this.userType = userType;
}


public User(String email, String username, String userType, ArrayList<ScheduleItem> scheduleIN) {
    this.email = email;
    this.username = username;
    this.userType = userType;
    this.schedule=scheduleIN;
}

public String getEmail() {
    return email;
}

public String getUsername() {
    return username;
}

public void setEmail(String email) {
    this.email = email;
}

public void setUsername(String username) {
    this.username = username;
}

public String getUserType() {
    return userType;
}

public void setUserType(String userType) {
    this.userType = userType;
}

public ArrayList<ScheduleItem> getSchedule() {
    return schedule;
}

public void setSchedule(ArrayList<ScheduleItem> scheduleIN) {
    this.schedule = scheduleIN;
}

}

here is my database

java - 我有一个用户类，它有一个私有字段 ArrayList

问题描述

解决方案

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