在 RecyclerView 上出错 position

Question

我试图在回收站视图中获取项目的 position 以便将其传递给其他活动，但在实际设法获取项目 ID 后，我发现我得到了 -1，因此没有得到那里有正确的身份证。 这可能是什么原因造成的？

活动：

package com.gmproxy.pastilarma;

import androidx.annotation.NonNull;
import androidx.appcompat.app.AlertDialog;
import androidx.appcompat.app.AppCompatActivity;
import androidx.lifecycle.ViewModelProvider;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;

import android.content.DialogInterface;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;
import android.widget.SearchView;
import android.widget.Toast;
import androidx.recyclerview.*;

import com.gmproxy.Adapters.PathologyListAdapter;
import com.gmproxy.Adapters.PathologyViewHolder;
import com.gmproxy.DAO.PathologyDAO;
import com.gmproxy.Entities.Pathology;
import com.gmproxy.Util.PathologyViewModel;


public class PathologiesSearchScreen extends AppCompatActivity {
    private PathologyViewModel viewModel;
    SearchView searchView;
    RecyclerView recyclerView;
    private PathologyDAO pathDao;
    private Pathology pathology;
    private PathologyViewHolder holder;

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

        searchView = findViewById(R.id.SearchView);
        recyclerView = findViewById(R.id.recyclerview);
        final PathologyListAdapter adapter = new PathologyListAdapter(new PathologyListAdapter.UserDiff());
        recyclerView.setAdapter(adapter);
        recyclerView.setLayoutManager(new LinearLayoutManager(this));

        viewModel = new ViewModelProvider(this).get(PathologyViewModel.class);
        viewModel.pathologies.observe(this, adapter::submitList);

        searchView.setOnQueryTextListener(new SearchView.OnQueryTextListener() {
            @Override
            public boolean onQueryTextSubmit(String query) {
                viewModel.setFilter(searchView.getQuery().toString());
                return false;
            }

            @Override
            public boolean onQueryTextChange(String newText) {
                long start;
                start = System.currentTimeMillis();
                if ((newText.length() > 3) && (System.currentTimeMillis() - start > 500)) {
                    viewModel.setFilter(searchView.getQuery().toString());
                }
                return false;
            }
        });

        recyclerView.addOnItemTouchListener(new RecyclerView.OnItemTouchListener() {
            @Override
            public boolean onInterceptTouchEvent(@NonNull @org.jetbrains.annotations.NotNull RecyclerView rv, @NonNull @org.jetbrains.annotations.NotNull MotionEvent e) {
                pathology = getSelectedPathology(findViewById(R.id.recyclerview));
                Log.println(Log.INFO, "PathologyTest", pathology.toString());
                final CharSequence[] options = {"Si", "No"};
                AlertDialog.Builder builder = new AlertDialog.Builder(PathologiesSearchScreen.this);
                builder.setTitle("¿Añadir la patología " + pathology.getPathologyName() + "?");
                builder.setItems(options, new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int item) {
                        if (options[item].equals("Si")) {
                            Toast.makeText(PathologiesSearchScreen.this, "Has añadido la patología " + pathology.getPathologyName() + ".", Toast.LENGTH_SHORT).show();
                            Intent mainAct = new Intent(PathologiesSearchScreen.this, UserAddScreen.class);
                            mainAct.putExtra("path", pathology);
                        } else if (options[item].equals("No")) {
                            dialog.dismiss();
                        }
                    }
                });
                builder.show();
                return true;
            }

            @Override
            public void onTouchEvent(@NonNull @org.jetbrains.annotations.NotNull RecyclerView rv, @NonNull @org.jetbrains.annotations.NotNull MotionEvent e) {
            }

            @Override
            public void onRequestDisallowInterceptTouchEvent(boolean disallowIntercept) {

            }
        });
    }


    public Pathology getSelectedPathology(View v){
        holder = new PathologyViewHolder(v);
        long idlongo = recyclerView.getAdapter().getItemId(holder.getAdapterPosition());
        Log.println(Log.INFO, "PathologyTest", String.valueOf(idlongo));
        int id = (int) idlongo;
        Pathology path = pathDao.findObjectbyId(id);
        return path;
    }


}

视图持有者：

package com.gmproxy.Adapters;

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Filter;
import android.widget.Filterable;
import android.widget.TextView;
import android.widget.Toast;

import androidx.recyclerview.widget.RecyclerView;

import com.gmproxy.DAO.PathologyDAO;
import com.gmproxy.Entities.Pathology;
import com.gmproxy.pastilarma.PathologiesSearchScreen;
import com.gmproxy.pastilarma.R;

import java.nio.file.Path;

public class PathologyViewHolder extends RecyclerView.ViewHolder {
    public final TextView objItemView;

    public PathologyViewHolder(View itemView) {
        super(itemView);
        objItemView = itemView.findViewById(R.id.textView);
    }

    public void bind(String text) {
        objItemView.setText(text);
    }

    static PathologyViewHolder create(ViewGroup parent) {
        View view = LayoutInflater.from(parent.getContext())
                .inflate(R.layout.pathologies_item, parent, false);
        return new PathologyViewHolder(view);
    }



}

列表适配器：

package com.gmproxy.Adapters;

import android.content.DialogInterface;
import android.content.Intent;
import android.util.Log;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Toast;

import androidx.annotation.NonNull;
import androidx.appcompat.app.AlertDialog;
import androidx.recyclerview.widget.DiffUtil;
import androidx.recyclerview.widget.ListAdapter;

import com.gmproxy.Entities.Pathology;
import com.gmproxy.pastilarma.PathologiesSearchScreen;
import com.gmproxy.pastilarma.UserAddScreen;


public class PathologyListAdapter extends ListAdapter<Pathology, PathologyViewHolder> {

    public PathologyListAdapter(@NonNull DiffUtil.ItemCallback<Pathology> diffCallback) {
        super(diffCallback);
    }

    @Override
    public PathologyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        return PathologyViewHolder.create(parent);
    }

    @Override
    public void onBindViewHolder(PathologyViewHolder holder, int position) {
        Pathology current = getItem(position);
        holder.bind(current.getPathologyName());
    }

    public static class UserDiff extends DiffUtil.ItemCallback<Pathology> {

        @Override
        public boolean areItemsTheSame(@NonNull Pathology oldItem, @NonNull Pathology newItem) {
            return oldItem == newItem;
        }

        @Override
        public boolean areContentsTheSame(@NonNull Pathology oldItem, @NonNull Pathology newItem) {
            return oldItem.getPathologyName().equals(newItem.getPathologyName());
        }
    }
}

实体 DAO：

package com.gmproxy.DAO;
import androidx.lifecycle.LiveData;
import androidx.room.*;

import com.gmproxy.Entities.Pathology;
import com.gmproxy.Entities.User;

import java.util.List;

@Dao
public interface PathologyDAO {
    @Query("SELECT * FROM condiciones")
    LiveData<List<Pathology>> getAllObjects();

    //This will come in handy for getting all those pathologies, will need to get them on a for loop since I'm not completely sure
    //that the query will handle int[]
    @Query("SELECT id_condiciones FROM condiciones WHERE id_condiciones LIKE :id_condiciones")
    int getPathologiesForUser(int id_condiciones);

    @Query("SELECT nombreCondicion FROM condiciones WHERE nombreCondicion LIKE :pathologyName")
    String getPathologiesForName(String pathologyName);

    @Query("SELECT * FROM condiciones WHERE nombreCondicion LIKE :pathologyName")
    Pathology getPathologiesCompleteForName(String pathologyName);

    @Query("SELECT * FROM condiciones WHERE id_condiciones = :id")
    Pathology findObjectbyId(int id);

    @Query("SELECT * FROM condiciones WHERE nombreCondicion LIKE '%' || :filter || '%'")
    LiveData<List<Pathology>> filterText(String filter);

    @Insert(onConflict = OnConflictStrategy.REPLACE)
    void insertAllObjects(List<Pathology> listObjects);


    @Insert(onConflict = OnConflictStrategy.REPLACE)
    void insertObject(Pathology object);

    @Update
    void updateObject(Pathology object);

    @Delete
    void delete(Pathology obj);


}

实体存储库：

package com.gmproxy.DAO;

import android.app.Application;
import android.os.AsyncTask;

import androidx.lifecycle.LiveData;

import com.gmproxy.Entities.Pathology;
import com.gmproxy.Entities.User;

import java.util.List;
import java.util.concurrent.ExecutionException;

public class PathologyRepository {
    private PathologyDAO concerningDao;
    private LiveData<List<Pathology>> pathologyList;

    public PathologyRepository(Application application) {
        DatabaseHelper db = DatabaseHelper.getDatabase(application);
        concerningDao = db.pathologyDao();
        pathologyList = concerningDao.getAllObjects();
    }

    public LiveData<List<Pathology>> getAllObjects() {
        return concerningDao.getAllObjects();
    }

    void insertAllObjects(List<Pathology> objectsList) {
        DatabaseHelper.databaseWriteExecutor.execute(() ->{
            concerningDao.insertAllObjects(objectsList);
        });
    }

    public void insertObject(Pathology obj){
        DatabaseHelper.databaseWriteExecutor.execute(() ->{
            concerningDao.insertObject(obj);
        });
    }

    public void deleteObject(Pathology obj) {
        concerningDao.delete(obj);
    }

    public LiveData<List<Pathology>> filter(String input){
        try{
            return new FilterNoteAsyncTask(concerningDao).execute(input).get();
        } catch (ExecutionException | InterruptedException e) {
            e.printStackTrace();
        }
        return null;
    }

    private static class FilterNoteAsyncTask extends AsyncTask<String, Void, LiveData<List<Pathology>>> {
        private PathologyDAO pathologyDAO;

        private FilterNoteAsyncTask(PathologyDAO pathologyDAO) {
            this.pathologyDAO = pathologyDAO;
        }

        @Override
        protected LiveData<List<Pathology>> doInBackground(String... strings) {
            return pathologyDAO.filterText(strings[0]);
        }
    }
}

Answer 1

将您的 PathologyListAdapter 移动到全局，并使用适配器 object 获取适配器 position，而不是从 recyclerview 获取适配器。

公共病理学 getSelectedPathology(){ long idlongo = adapter.getAdapterPosition(); Log.println(Log.INFO, "PathologyTest", String.valueOf(idlongo)); int id = (int) idlongo; 病理路径 = pathDao.findObjectbyId(id); 返回路径； }