Exception à mydrawer.setDrawerListener (myactiontoggle) dans Android

Question

J'utilise le tiroir dans mon projet, mais parfois il jette NullPointerException, voici mon code où je suis exception:

DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout); 
    toggle = new ActionBarDrawerToggle(TabSample.this, drawer, null, R.string.navigation_drawer_open, R.string.navigation_drawer_close); 
    drawer.setDrawerListener(toggle);//here i got exception 
    toggle.syncState(); 

Et l'erreur ci-dessous je suis arrivé:

01-23 11:53:20.370 16530-16530/com.myproject.myproject1 E/AndroidRuntime: FATAL EXCEPTION: main 
    java.lang.RuntimeException: Unable to start activity ComponentInfo{com.myproject.myproject1/com.myproject.myproject1.TabSample}: java.lang.NullPointerException 
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1970) 
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1995) 
    at android.app.ActivityThread.access$600(ActivityThread.java:128) 
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1161) 
    at android.os.Handler.dispatchMessage(Handler.java:99) 
    at android.os.Looper.loop(Looper.java:137) 
    at android.app.ActivityThread.main(ActivityThread.java:4517) 
    at java.lang.reflect.Method.invokeNative(Native Method) 
    at java.lang.reflect.Method.invoke(Method.java:511) 
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:993) 
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:760) 
    at dalvik.system.NativeStart.main(Native Method) 
    Caused by: java.lang.NullPointerException 
    at android.support.v7.app.ActionBarDrawerToggle$HoneycombDelegate.setActionBarUpIndicator(ActionBarDrawerToggle.java:539) 
    at android.support.v7.app.ActionBarDrawerToggle.setActionBarUpIndicator(ActionBarDrawerToggle.java:458) 
    at android.support.v7.app.ActionBarDrawerToggle.syncState(ActionBarDrawerToggle.java:245) 
    at com.myproject.myproject1.TabSample.setDrawer(TabSample.java:109) 
    at com.myproject.myproject1.TabSample.onCreate(TabSample.java:77) 
    at android.app.Activity.performCreate(Activity.java:4470) 
    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1053) 
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1934) 
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1995)  
    at android.app.ActivityThread.access$600(ActivityThread.java:128)  
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1161)  
    at android.os.Handler.dispatchMessage(Handler.java:99)  
    at android.os.Looper.loop(Looper.java:137)  
    at android.app.ActivityThread.main(ActivityThread.java:4517)  
    at java.lang.reflect.Method.invokeNative(Native Method)  
    at java.lang.reflect.Method.invoke(Method.java:511)  
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:993)  
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:760)  
    at dalvik.system.NativeStart.main(Native Method)  

s'il vous plaît aider à résoudre son NullPointerException dans ActionBarDrawerToggle.

Cette question pas seulement comme exception NullPointerException me dire démultiplient comme: NullpointerException

Answer 1

dans le code ci-dessus, vous avez la barre d'outils passe comme thats null pourquoi vous donne son java.lang.NullPointerException

Voici un exemple de code

toolbar = (Toolbar) findViewById(R.id.toolbar); 
    setSupportActionBar(toolbar); 
drawer = (DrawerLayout) findViewById(R.id.drawer_layout); 

ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(
      this, drawer, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close); 
    drawer.addDrawerListener(toggle); 
    toggle.syncState();