Исключение Nullpointer - FragmentActivity

Question

Я получил ошибку исключения nullpointer в моей функции фрагментации.

Ниже журнал кошка:

11-04 06:29:51.550: E/AndroidRuntime(19286): FATAL EXCEPTION: main 
11-04 06:29:51.550: E/AndroidRuntime(19286): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.dooba.beta/com.dooba.beta.MainActivity}: java.lang.NullPointerException 
11-04 06:29:51.550: E/AndroidRuntime(19286): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2059) 
11-04 06:29:51.550: E/AndroidRuntime(19286): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2084) 
11-04 06:29:51.550: E/AndroidRuntime(19286): at android.app.ActivityThread.access$600(ActivityThread.java:130) 
11-04 06:29:51.550: E/AndroidRuntime(19286): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1195) 
11-04 06:29:51.550: E/AndroidRuntime(19286): at android.os.Handler.dispatchMessage(Handler.java:99) 
11-04 06:29:51.550: E/AndroidRuntime(19286): at android.os.Looper.loop(Looper.java:137) 
11-04 06:29:51.550: E/AndroidRuntime(19286): at android.app.ActivityThread.main(ActivityThread.java:4745) 
11-04 06:29:51.550: E/AndroidRuntime(19286): at java.lang.reflect.Method.invokeNative(Native Method) 
11-04 06:29:51.550: E/AndroidRuntime(19286): at java.lang.reflect.Method.invoke(Method.java:511) 
11-04 06:29:51.550: E/AndroidRuntime(19286): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786) 
11-04 06:29:51.550: E/AndroidRuntime(19286): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553) 
11-04 06:29:51.550: E/AndroidRuntime(19286): at dalvik.system.NativeStart.main(Native Method) 
11-04 06:29:51.550: E/AndroidRuntime(19286): Caused by: java.lang.NullPointerException 
11-04 06:29:51.550: E/AndroidRuntime(19286): at com.dooba.beta.MainActivity.onCreate(MainActivity.java:51) 
11-04 06:29:51.550: E/AndroidRuntime(19286): at android.app.Activity.performCreate(Activity.java:5008) 
11-04 06:29:51.550: E/AndroidRuntime(19286): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1079) 
11-04 06:29:51.550: E/AndroidRuntime(19286): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2023) 
11-04 06:29:51.550: E/AndroidRuntime(19286): ... 11 more 

Я считаю, что ошибка происходит в этих строках:

mDrawerList.setAdapter(new ArrayAdapter<String>(getActionBar() 
     .getThemedContext(), android.R.layout.simple_list_item_1, 
     mOptionMenu)); 

Ниже весь код вида деятельности:

import android.app.ActionBar; 
import android.app.Activity; 
import android.content.res.Configuration; 
import android.os.Bundle; 
import android.support.v4.app.ActionBarDrawerToggle; 
import android.support.v4.app.ActivityCompat; 
import android.support.v4.app.Fragment; 
import android.support.v4.app.FragmentActivity; 

import android.support.v4.app.FragmentManager; 
import android.support.v4.widget.DrawerLayout; 
import android.view.Menu; 
import android.view.MenuItem; 
import android.support.v7.app.ActionBarActivity; 
import android.view.View; 
import android.widget.AdapterView; 
import android.widget.AdapterView.OnItemClickListener; 
import android.widget.ArrayAdapter; 
import android.widget.ListView; 
import android.widget.RelativeLayout; 
import android.widget.Toast; 

public class MainActivity extends FragmentActivity { 

    private String[] mOptionMenu; 
    private DrawerLayout mDrawerLayout; 
    private RelativeLayout mDrawerRelativeLayout; 
    private ListView mDrawerList; 
    private ActionBarDrawerToggle mDrawerToggle; 

    private CharSequence mTitleSection; 
    private CharSequence mTitleApp; 

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



     mOptionMenu = new String[] { "Opción 1", "Opción 2", "Opción 3" }; 
     mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout); 
     mDrawerRelativeLayout = (RelativeLayout) 
     findViewById(R.id.left_drawer); 
     mDrawerList = (ListView) findViewById(R.id.list_view_drawer); 
     mDrawerList.setAdapter(new ArrayAdapter<String>(getActionBar() 
     .getThemedContext(), android.R.layout.simple_list_item_1, 
     mOptionMenu)); 

     mDrawerList.setOnItemClickListener(new OnItemClickListener() { 
     @Override 
     public void onItemClick(AdapterView<?> parent, View view, 
     int position, long id) { 

     Fragment fragment = null; 

     switch (position) { 
     case 0: 
     fragment = new FirstFragment(); 
     break; 
     case 1: 
     fragment = new SecondFragment(); 
     break; 
     case 2: 
     fragment = new ThirdFragment(); 
     break; 
     } 

     FragmentManager fragmentManager = getSupportFragmentManager(); 

     fragmentManager.beginTransaction() 
     .replace(R.id.content_frame, fragment).commit(); 

     mDrawerList.setItemChecked(position, true); 

     mTitleSection = mOptionMenu[position]; 
     getActionBar().setTitle(mTitleSection); 

     mDrawerLayout.closeDrawer(mDrawerRelativeLayout); 
     } 
     }); 
     mDrawerList.setItemChecked(0, true); 
     mTitleSection = getTitle(); 
     mTitleApp = getTitle(); 

     mDrawerToggle = new ActionBarDrawerToggle(this, mDrawerLayout, 
     R.drawable.ic_drawer, R.string.drawer_open, 
     R.string.drawer_close) { 

     public void onDrawerClosed(View view) { 
     getActionBar().setTitle(mTitleSection); 
     ActivityCompat.invalidateOptionsMenu(MainActivity.this); 
     } 

     public void onDrawerOpened(View drawerView) { 
     getActionBar().setTitle(mTitleSection); 
     ActivityCompat.invalidateOptionsMenu(MainActivity.this); 
     } 
     }; 

     mDrawerLayout.setDrawerListener(mDrawerToggle); 

     getActionBar().setDisplayHomeAsUpEnabled(true); 
     getActionBar().setHomeButtonEnabled(true); 
    } 

    @Override 
    public boolean onCreateOptionsMenu(Menu menu) { 

     getMenuInflater().inflate(R.menu.main_activity_actions, menu); 
     return true; 
    } 

    @Override 
    public boolean onOptionsItemSelected(MenuItem item) { 

     if (mDrawerToggle.onOptionsItemSelected(item)) { 
      return true; 
     } 

     switch (item.getItemId()) { 
     case R.id.action_settings: 
      Toast.makeText(this, "Settings", Toast.LENGTH_SHORT).show(); 
      ; 
      break; 
     default: 
      return super.onOptionsItemSelected(item); 
     } 

     return true; 
    } 

    @Override 
    protected void onPostCreate(Bundle savedInstanceState) { 
     super.onPostCreate(savedInstanceState); 
     mDrawerToggle.syncState(); 
    } 

    @Override 
    public void onConfigurationChanged(Configuration newConfig) { 
     super.onConfigurationChanged(newConfig); 
     mDrawerToggle.onConfigurationChanged(newConfig); 
    } 
} 

Если какое-либо разъяснение необходимо, дайте мне знать. Спасибо заранее.

Answer 1

Вместо

getActionBar().getThemedContext() 

использование this

Answer 2

Поскольку вы импортируете импорта android.support.v7.app.ActionBarActivity, я думаю, вы должны использовать

getSupportActionBar() 

вместо

getActionBar()