java - 在同一个回收站视图中显示两个实时数据列表

Question

我试过的：我认为这个问题适合使用 MediatorLiveData，但是我不确定如何将它应用到我的代码中，因为我在网上发现的用法主要用于 Kotlin。目前，我正在尝试将 MVVM 方案与 2 个实体（BPcheck、MEDtaken）及其对应的 Dao 和 View Models、一个存储库、一个数据库和一个 RecyclerViewAdapter 一起使用。最初，我尝试创建 Recording 的 BPcheck 和 MEDtaken 子类，但是我遇到了类型转换的问题。接下来我尝试让每个单独的类，但后来遇到了不理解在同一个 recyclerview 中显示两个 LiveData 列表的问题。

目标：我试图在同一个 RecyclerView 中显示来自两个 LiveData 列表的数据，并根据数据类型膨胀不同的 Recyclerview 布局。将来我想在这个 Recyclerview 中添加更多的 LiveData 列表，每个列表都有自己的布局。

背景：我一直在关注以下视频系列来帮助创建应用程序：https ://www.youtube.com/watch?v=Jwdty9jQN0E&ab_channel=CodinginFlow

我的代码：

public class RecordingsRecyclerViewAdapter extends RecyclerView.Adapter{

    final int VIEW_TYPE_MEDTAKEN = 0;
    final int VIEW_TYPE_BPCHECK = 1;

    private List<MedTaken> medTakenList = new ArrayList<>();
    private List<BPcheck> bpChecksList = new ArrayList<>();
    
    // !! Ideally, this recordingsList would hold both lists. !!//
    private List<Object> recordingsList = new ArrayList<>();

    private Context recordings_context;

    public RecordingsRecyclerViewAdapter(Context recordings_context) {
        this.recordings_context = recordings_context;
    }

    @Override
    // My Attempt at trying to get different datatypes to inflate different layouts
    public int getItemViewType(int position) {
        if (recordingsList.get(position) instanceof BPcheck){
            return 1;
        }else{
            return 0;
        }
    }

    @NonNull
    @Override
    public RecyclerView.ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        LayoutInflater layoutInflater = LayoutInflater.from(parent.getContext());
        View view;

        if (viewType == VIEW_TYPE_BPCHECK) {
            view = layoutInflater.inflate(R.layout.recordings_bloodpressurecheck_item, parent, false);
            return new ViewHolder_BPCHECK(view);
        }
        if(viewType==VIEW_TYPE_MEDTAKEN) {
            view = layoutInflater.inflate(R.layout.recordings_medtaken_item, parent, false);
            return new ViewHolder_MEDTAKEN(view);
        }
        return null;

    }

    @Override
    public void onBindViewHolder(@NonNull RecyclerView.ViewHolder holder, int position) {
        if(holder.getItemViewType()==1){
            //bind viewholder2
            ViewHolder_BPCHECK viewHolder_bpcheck = (ViewHolder_BPCHECK) holder;
            viewHolder_bpcheck.systolic.setText(((BPcheck) recordingsList.get(position)).getSystolicBP());
        }else{
            ViewHolder_MEDTAKEN viewHolder_medtaken = (ViewHolder_MEDTAKEN) holder;
            viewHolder_medtaken.subtitle.setText(((MedTaken) recordingsList.get(position)).getMedication().getMedCommonName());
        }

    }

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


    class ViewHolder_MEDTAKEN extends RecyclerView.ViewHolder{

        TextView datetime,subtitle;

        public ViewHolder_MEDTAKEN(@NonNull View itemView) {
            super(itemView);

            datetime = itemView.findViewById(R.id.txt_recording_datetime);
            subtitle = itemView.findViewById(R.id.txt_recording_subtitle);
        }
    }

    class ViewHolder_BPCHECK extends RecyclerView.ViewHolder{

        TextView datetime,systolic,diastolic;
        public ViewHolder_BPCHECK(@NonNull View itemView) {
            super(itemView);

            datetime = itemView.findViewById(R.id.txt_bpCheck_datetime);
            systolic = itemView.findViewById(R.id.txt_systolic);
            diastolic = itemView.findViewById(R.id.txt_diastolic);
        }
    }

public class AllRecordingsActivity extends AppCompatActivity {
    
    // !! RecordingViewModel is not created, but I just wanted to give an idea of where I was trying to go with this
    private RecordingViewModel recordingViewModel;

    private RecyclerView recordingsRecyclerView;
    private RecordingsRecyclerViewAdapter recordingsRecyclerViewAdapter;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_all_recordings);

        recordingsRecyclerView  = findViewById(R.id.recordingsRecyclerView);


        recordingsRecyclerViewAdapter = new RecordingsRecyclerViewAdapter(this);

        recordingsRecyclerView.setAdapter(recordingsRecyclerViewAdapter);
        recordingsRecyclerView.setLayoutManager(new GridLayoutManager(this,1));

        // !! not really sure what to do here
        recordingViewModel = new ViewModelProvider(this).get(RecordingViewModel.class);
        recordingViewModel.getAllRecordings().observe(this, new Observer<List<Recording>>() {
            @Override
            public void onChanged(List<Recording> recordings) {
                recordingsRecyclerViewAdapter.setRecordingsList(recordings);
            }
        });
}

public class PatientRepository {
    private MedicationDao medicationDao;
    private BPcheckDao bpCheckDao;

    private LiveData<List<Medication>> allMedications;
    private LiveData<List<MedTaken>> allMedTaken;
    private LiveData<List<BPcheck>> allBPchecks;

    public PatientRepository(Application application){
        PatientDatabase database = PatientDatabase.getInstance(application);

        medTakenDao= database.medTakenDao();
        allMedTaken = medTakenDao.getAllMedTaken();

        bpCheckDao= database.bpCheckDao();
        allBPchecks = bpCheckDao.getAllBPchecks();

    }

    // MedTaken Methods

    public void addToMedTaken(MedTaken medTaken){
        new InsertMedTakenAsyncTask(medTakenDao).execute(medTaken);
    }
    public void updateMedTaken(MedTaken medTaken){
        new UpdateMedTakenAsyncTask(medTakenDao).execute(medTaken);
    }
    public void deleteMedTaken(MedTaken medTaken){
        new DeleteMedTakenAsyncTask(medTakenDao).execute(medTaken);
    }

    public LiveData<List<MedTaken>> getAllMedTaken() {
        return allMedTaken;
    }


    // MedTaken ASYNC Tasks

    private static class InsertMedTakenAsyncTask extends AsyncTask<MedTaken,Void,Void>{
        private MedTakenDao medTakenDao;

        private InsertMedTakenAsyncTask(MedTakenDao medTakenDao){
            this.medTakenDao = medTakenDao;
        }
        @Override
        protected Void doInBackground(MedTaken... medTaken) {
            medTakenDao.insert(medTaken[0]);
            return null;
        }
    }

    private static class UpdateMedTakenAsyncTask extends AsyncTask<MedTaken,Void,Void>{
        private MedTakenDao medTakenDao;

        private UpdateMedTakenAsyncTask(MedTakenDao medTakenDao){
            this.medTakenDao = medTakenDao;
        }
        @Override
        protected Void doInBackground(MedTaken... medTaken) {
            medTakenDao.update(medTaken[0]);
            return null;
        }
    }

    private static class DeleteMedTakenAsyncTask extends AsyncTask<MedTaken,Void,Void>{
        private MedTakenDao medTakenDao;

        private DeleteMedTakenAsyncTask(MedTakenDao medTakenDao){
            this.medTakenDao = medTakenDao;
        }
        @Override
        protected Void doInBackground(MedTaken... medTaken) {
            medTakenDao.delete(medTaken[0]);
            return null;
        }
    }

    //BP Checks methods

    public void addToBPchecks(BPcheck bpCheck){
        new InsertBPchecksAsyncTask(bpCheckDao).execute(bpCheck);
    }
    public void updateBPchecks(BPcheck bpCheck){
        new UpdateBPchecksAsyncTask(bpCheckDao).execute(bpCheck);
    }
    public void deleteBPchecks(BPcheck bpCheck){
        new DeleteBPchecksAsyncTask(bpCheckDao).execute(bpCheck);
    }

    public LiveData<List<BPcheck>> getAllBPchecks() {
        return allBPchecks;
    }


    // BPChecks ASYNC Tasks

    private static class InsertBPchecksAsyncTask extends AsyncTask<BPcheck,Void,Void>{
        private BPcheckDao bpCheckDao;

        private InsertBPchecksAsyncTask(BPcheckDao bpCheckDao){
            this.bpCheckDao = bpCheckDao;
        }
        @Override
        protected Void doInBackground(BPcheck... bpChecks) {
            bpCheckDao.insert(bpChecks[0]);
            return null;
        }
    }

    private static class UpdateBPchecksAsyncTask extends AsyncTask<BPcheck,Void,Void>{
        private BPcheckDao bpCheckDao;

        private UpdateBPchecksAsyncTask(BPcheckDao bpCheckDao){
            this.bpCheckDao = bpCheckDao;
        }
        @Override
        protected Void doInBackground(BPcheck... bpChecks) {
            bpCheckDao.update(bpChecks[0]);
            return null;
        }
    }

    private static class DeleteBPchecksAsyncTask extends AsyncTask<BPcheck,Void,Void>{
        private BPcheckDao bpCheckDao;

        private DeleteBPchecksAsyncTask(BPcheckDao bpCheckDao){
            this.bpCheckDao = bpCheckDao;
        }
        @Override
        protected Void doInBackground(BPcheck... bpChecks) {
            bpCheckDao.delete(bpChecks[0]);
            return null;
        }
    }

@Entity(tableName = "BPcheck_table")
public class BPcheck {

    @PrimaryKey(autoGenerate = true)
    private int id;

    private String date;
    private String timestamp;
    private int systolicBP;
    private int diastolicBP;
    private String comments;

    public BPcheck(String date, String timestamp, int systolicBP, int diastolicBP, String comments) {
        this.date = date;
        this.timestamp = timestamp;
        this.systolicBP = systolicBP;
        this.diastolicBP = diastolicBP;
        this.comments = comments;
    }


    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getDate() {
        return date;
    }

    public void setDate(String date) {
        this.date = date;
    }

    public String getTimestamp() {
        return timestamp;
    }

    public void setTimestamp(String timestamp) {
        this.timestamp = timestamp;
    }

    public int getSystolicBP() {
        return systolicBP;
    }

    public void setSystolicBP(int systolicBP) {
        this.systolicBP = systolicBP;
    }

    public int getDiastolicBP() {
        return diastolicBP;
    }

    public void setDiastolicBP(int diastolicBP) {
        this.diastolicBP = diastolicBP;
    }

    public String getComments() {
        return comments;
    }

    public void setComments(String comments) {
        this.comments = comments;
    }
}

@Dao
public interface BPcheckDao {

    @Insert
    void insert(BPcheck BPcheck);

    @Update
    void update(BPcheck BPcheck);

    @Delete
    void delete(BPcheck BPcheck);

    @Query("SELECT * FROM BPcheck_table")
    LiveData<List<BPcheck>> getAllBPchecks();

}

public class RecordingsViewModel extends AndroidViewModel {
    private PatientRepository repository;
    private LiveData<List<MedTaken>> allMedTaken;
    private LiveData<List<BPcheck>> allBPChecks;
    private MediatorLiveData allRecordings;


    public RecordingsViewModel(@NonNull Application application) {
        super(application);
        repository = new PatientRepository(application);

    }

    public LiveData<List<Object>> getAllRecordings() {
        return allRecordings;
    }

}

@Entity(tableName = "MedTaken_table")
public class MedTaken {

    private int id;
    private Medication medication;
    private String comments;
    private String date;
    private String timestamp;

    public MedTaken(Medication medication, String comments, String date, String timestamp) {
        this.medication = medication;
        this.comments = comments;
        this.date = date;
        this.timestamp = timestamp;
    }

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public Medication getMedication() {
        return medication;
    }

    public void setMedication(Medication medication) {
        this.medication = medication;
    }

    public String getComments() {
        return comments;
    }

    public void setComments(String comments) {
        this.comments = comments;
    }

    public String getDate() {
        return date;
    }

    public void setDate(String date) {
        this.date = date;
    }

    public String getTimestamp() {
        return timestamp;
    }

    public void setTimestamp(String timestamp) {
        this.timestamp = timestamp;
    }
}

@Dao
public interface MedTakenDao {
    @Insert
    void insert(MedTaken medTaken);

    @Update
    void update(MedTaken medTaken);

    @Delete
    void delete(MedTaken medTaken);

    @Query("SELECT * FROM MedTaken_table")
    LiveData<List<MedTaken>> getAllMedTaken();
}

public class MedTakenViewModel extends AndroidViewModel {

    private PatientRepository repository;
    private LiveData<List<MedTaken>> allMedTaken;

    public MedTakenViewModel(@NonNull Application application) {
        super(application);
        repository = new PatientRepository(application);
        allMedTaken = repository.getAllMedTaken();
    }

    public void insert(MedTaken medTaken){ repository.addToMedTaken(medTaken); }

    public void update(MedTaken medTaken){ repository.updateMedTaken(medTaken); }

    public void delete(MedTaken medTaken){ repository.deleteMedTaken(medTaken); }

    public LiveData<List<MedTaken>> getAllMedTaken() {
        return allMedTaken;
    }
}

标签： javaandroidandroid-recyclerviewandroid-livedata