android.support.v4.widget.DrawerLayout не может быть отброшен в android.support.v4.widget.DrawerLayout $ DrawerListener

Question

Я получаю DrawerLayout не может быть запущена ошибка и мои приложения crashes.I я новичок в android Помогите мне

Вот мой MainAvtivity

public class MainActivity extends AppCompatActivity { 

private Toolbar toolbar; 

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_main); 
    toolbar = (Toolbar) findViewById(R.id.app_bar); 
    setSupportActionBar(toolbar); 
    getSupportActionBar().setDisplayShowHomeEnabled(true); 
    NavigationDrawerFragment drawerFragment = (NavigationDrawerFragment) 
     getSupportFragmentManager().findFragmentById(R.id.fragment_navigation_drawer); 
    drawerFragment.setUp((DrawerLayout) findViewById(R.id.drawer_layout),toolbar); 

} 


@Override 
public boolean onCreateOptionsMenu(Menu menu) { 
    // Inflate the menu; this adds items to the action bar if it is present. 
    getMenuInflater().inflate(R.menu.menu_main, menu); 
    return true; 
} 

@Override 
public boolean onOptionsItemSelected(MenuItem item) { 
    // Handle action bar item clicks here. The action bar will 
    // automatically handle clicks on the Home/Up button, so long 
    // as you specify a parent activity in AndroidManifest.xml. 
    int id = item.getItemId(); 

    //noinspection SimplifiableIfStatement 
    if (id == R.id.action_settings) { 
     return true; 
    } 

    return super.onOptionsItemSelected(item); 
} 

}

Здесь Activitymain.xml

<android.support.v4.widget.DrawerLayout xmlns:android="http://schemas.android.com/apk/res/android" 
xmlns:app="http://schemas.android.com/apk/res-auto" 
xmlns:tools="http://schemas.android.com/tools" 
android:id="@+id/drawer_layout" 
android:layout_width="match_parent" 
android:layout_height="match_parent"> 


<RelativeLayout 
    android:layout_width="match_parent" 
    android:layout_height="match_parent" 
    tools:context=".MainActivity"> 

    <include 
     android:id="@+id/app_bar" 
     layout="@layout/app_bar" /> 

    <TextView 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:layout_below="@+id/app_bar" 

     android:text="@string/hello_world" /> 

</RelativeLayout> 

<fragment 
    android:id="@+id/fragment_navigation_drawer" 
    android:name="com.appdego.rosesketch.NavigationDrawerFragment" 
    android:layout_width="@dimen/nav_drawer_width" 
    android:layout_height="match_parent" 
    android:layout_gravity="start" 
    app:layout="@layout/fragment_navigation_drawer" 
    tools:layout="@layout/fragment_navigation_drawer" /> 

Мой NavigationDrawerFragment.java код

public class NavigationDrawerFragment extends Fragment { 

private ActionBarDrawerToggle mDrawerToggle; 
private DrawerLayout mDrawerLayout; 

public NavigationDrawerFragment() { 
    // Required empty public constructor 
} 


@Override 
public View onCreateView(LayoutInflater inflater, ViewGroup container, 
         Bundle savedInstanceState) { 
    // Inflate the layout for this fragment 
    return inflater.inflate(R.layout.fragment_navigation_drawer, container, false); 
} 


public void setUp(DrawerLayout drawerLayout, Toolbar toolbar) { 
    mDrawerLayout = drawerLayout; 
    mDrawerToggle = new ActionBarDrawerToggle(getActivity(), (DrawerLayout) drawerLayout, toolbar, R.string.drawer_open, R.string.drawer_close) { 
     @Override 
     public void onDrawerOpened(View drawerView) { 
      super.onDrawerOpened(drawerView); 
     } 

     @Override 
     public void onDrawerClosed(View drawerView) { 
      super.onDrawerClosed(drawerView); 
     } 
    }; 
    mDrawerLayout.setDrawerListener((DrawerListener) mDrawerLayout); 
} 

}

и fragment_navigation_drawer.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" 
xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" 
android:layout_height="match_parent" 
tools:context="com.appdego.rosesketch.NavigationDrawerFragment"> 

<!-- TODO: Update blank fragment layout --> 
<TextView android:layout_width="match_parent" android:layout_height="match_parent" 
    android:text="@string/hello_blank_fragment" /> 

LogCat:

java.lang.RuntimeException: Unable to start activity ComponentInfo{com.appdego.rosesketch/com.appdego.rosesketch.MainActivity}: java.lang.ClassCastException: android.support.v4.widget.DrawerLayout cannot be cast to android.support.v4.widget.DrawerLayout$DrawerListener 
     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2338) 
     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2390) 
     at android.app.ActivityThread.access$800(ActivityThread.java:151) 
     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1321) 
     at android.os.Handler.dispatchMessage(Handler.java:110) 
     at android.os.Looper.loop(Looper.java:193) 
     at android.app.ActivityThread.main(ActivityThread.java:5292) 
     at java.lang.reflect.Method.invokeNative(Native Method) 
     at java.lang.reflect.Method.invoke(Method.java:515) 
     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:824) 
     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:640) 
     at dalvik.system.NativeStart.main(Native Method) 
Caused by: java.lang.ClassCastException: android.support.v4.widget.DrawerLayout cannot be cast to android.support.v4.widget.DrawerLayout$DrawerListener 
     at com.appdego.rosesketch.NavigationDrawerFragment.setUp(NavigationDrawerFragment.java:49) 
     at com.appdego.rosesketch.MainActivity.onCreate(MainActivity.java:25) 
     at android.app.Activity.performCreate(Activity.java:5264) 
     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1088) 

Я следую slidenerd материал Дизайн Учебники

Answer 1

Вам нужно внести изменения кода ниже:

// Set the drawer toggle as the DrawerListener 
     mDrawerLayout.setDrawerListener(mDrawerToggle); 

Answer 2

Проблема в этой строке: mDrawerLayout.setDrawerListener((DrawerListener) mDrawerLayout); Вы должны установить слушателя, но вы типа Кастинг DrawerLayout к DrawerListener.

Предлагаю полностью удалить эту линию, поскольку она не нужна. Если вы действительно хотите установить слушателя, вы должны сделать это, как показано ниже:

 mDrawerLayout.setDrawerListener(new DrawerLayout.DrawerListener() { 
      @Override 
      public void onDrawerSlide(View drawerView, float slideOffset) { 

      } 

      @Override 
      public void onDrawerOpened(View drawerView) { 

      } 

      @Override 
      public void onDrawerClosed(View drawerView) { 

      } 

      @Override 
      public void onDrawerStateChanged(int newState) { 

      } 
     });