Question

我正在尝试使用configureOnClickRecyclerView方法返回recyclerView的每个元素的位置，但是在编译时，Android Studio给我一个错误：

E / Android运行时：致命异常：主要流程：com.example.iaitmansour.myfoot，PID：1241 java.lang.RuntimeException：无法启动活动ComponentInfo {com.example.iaitmansour.myfoot / com.example.iaitmansour.myfoot.MainActivity}：java.lang.NullPointerException：尝试调用虚拟方法'java.lang.Object android。在空对象引用上support.v7.widget.RecyclerView.getTag（int）'

出什么问题了？（对不起，英语是我法语）

package com.example.iaitmansour.myfoot;
import android.content.Intent;
import android.support.annotation.Nullable;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.Toolbar;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Toast;

import com.example.iaitmansour.myfoot.Adapter.ExistingClubsAdapter;
import com.example.iaitmansour.myfoot.Models.ExistingClubs;
import com.example.iaitmansour.myfoot.Models.ExistingClubsList;
import com.example.iaitmansour.myfoot.Utils.GetExistingClubsDataService;
import com.example.iaitmansour.myfoot.Utils.ItemClickSupport;
import com.example.iaitmansour.myfoot.Utils.RetrofitInstance;

import java.util.ArrayList;
import java.util.List;

import retrofit2.Call;
import retrofit2.Callback;
import retrofit2.Response;


public class MainActivity extends AppCompatActivity {

private ExistingClubsAdapter adapter;
private RecyclerView recyclerView;

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

    //Configuring Toolbar
    this.configureToolbar();


    /*Create handle for the RetrofitInstance interface*/
    GetExistingClubsDataService service = RetrofitInstance.getRetrofitInstance().create(GetExistingClubsDataService.class);

    /*Call the method with parameter in the interface to get the employee data*/
    Call<ExistingClubsList> call = service.getExistingClubsData();

    /*Log the URL called*/
    Log.wtf("URL Called", call.request().url() + "");

    call.enqueue(new Callback<ExistingClubsList>() {
        @Override
        public void onResponse(Call<ExistingClubsList> call, Response<ExistingClubsList> response) {
            generateExistingClubsList(response.body().getExistingClubsArrayList());
        }

        @Override
        public void onFailure(Call<ExistingClubsList> call, Throwable t) {
            Toast.makeText(MainActivity.this, "Something went wrong...Please try later!", Toast.LENGTH_SHORT).show();
        }
    });



    this.configureOnClickRecyclerView();

}


private void configureOnClickRecyclerView(){
    ItemClickSupport.addTo(recyclerView, R.layout.row_existing_clubs)
            .setOnItemClickListener(new ItemClickSupport.OnItemClickListener() {
                @Override
                public void onItemClicked(RecyclerView recyclerView, int position, View v) {
                    Log.e("TAG", "Position : "+position);
                }
            });
}



/*Method to generate List of employees using RecyclerView with custom adapter*/
private void generateExistingClubsList(List<ExistingClubs> empDataList) {
    recyclerView = findViewById(R.id.recycler_view_clubs_list);

    adapter = new ExistingClubsAdapter(MainActivity.this, empDataList);

    recyclerView.setLayoutManager(new LinearLayoutManager(MainActivity.this));

    recyclerView.setAdapter(adapter);

}



@Override
public boolean onCreateOptionsMenu(Menu menu) {
    //2 - Inflate the menu and add it to the Toolbar
    getMenuInflater().inflate(R.menu.menu_activity_main, menu);
    return true;
}


private void configureToolbar(){
    // Get the toolbar view inside the activity layout
    Toolbar toolbar = findViewById(R.id.activity_main_toolbar);
    // Sets the Toolbar
    setSupportActionBar(toolbar);
    getSupportActionBar().setTitle(null);
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    //Handle actions on menu items
    switch (item.getItemId()) {
        case R.id.menu_activity_main_add:
            Intent addClubActivity = new Intent(MainActivity.this, AddClubActivity.class);
            startActivity(addClubActivity);
        default:
            return super.onOptionsItemSelected(item);
    }
}

}

RecyclerView java.lang.NullPointerException：尝试调用虚拟方法

0 个答案: