Null Pointer Exception - Android Fragmanı'nda Düğme

Şu anda Android'de Fragment ve Activity arasındaki iletişim üzerinde çalışıyorum. Burada ulaşmak istediğim, Fragman'ın bir düğmesinde ClickListener'da ayarlandı. Ancak, NPE oluşur ve nedenini bulamıyorum. Yığın akışıyla ilgili birçok benzer soru var ama benim için çalışan bir tane bulamadım. Aşağıda benim kodum ve logcat vardır. Bir süreliğine burada kalmış ve birisinin bana yardımcı olabileceğini umuyorum!Null Pointer Exception - Android Fragmanı'nda Düğme

Logcat:

> 04-14 17:53:02.163 15136-15136/? E/AndroidRuntime: java.lang.RuntimeException: Unable to start activity 
> ComponentInfo{com.example.ivylin.corewar/com.example.ivylin.corewar.assistantWidgets.WarriorBattleSelfScreen}: 
> android.view.InflateException: Binary XML file line #7: Error 
> inflating class fragment 
>  04-14 17:53:02.163 15136-15136/? E/AndroidRuntime:  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2298) 
>  04-14 17:53:02.163 15136-15136/? E/AndroidRuntime:  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2360) 
>  04-14 17:53:02.163 15136-15136/? E/AndroidRuntime:  at android.app.ActivityThread.access$800(ActivityThread.java:144) 
>  04-14 17:53:02.163 15136-15136/? E/AndroidRuntime:  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1278) 
>  04-14 17:53:02.163 15136-15136/? E/AndroidRuntime:  at android.os.Handler.dispatchMessage(Handler.java:102) 
>  04-14 17:53:02.163 15136-15136/? E/AndroidRuntime:  at android.os.Looper.loop(Looper.java:135) 
>  04-14 17:53:02.163 15136-15136/? E/AndroidRuntime:  at android.app.ActivityThread.main(ActivityThread.java:5221) 
>  04-14 17:53:02.163 15136-15136/? E/AndroidRuntime:  at java.lang.reflect.Method.invoke(Native Method) 
>  04-14 17:53:02.163 15136-15136/? E/AndroidRuntime:  at java.lang.reflect.Method.invoke(Method.java:372) 
>  04-14 17:53:02.163 15136-15136/? E/AndroidRuntime:  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899) 
>  04-14 17:53:02.163 15136-15136/? E/AndroidRuntime:  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694) 
>  04-14 17:53:02.163 15136-15136/? E/AndroidRuntime: Caused by: android.view.InflateException: Binary XML file line #7: Error 
> inflating class fragment 
>  04-14 17:53:02.163 15136-15136/? E/AndroidRuntime:  at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:763) 
>  04-14 17:53:02.163 15136-15136/? E/AndroidRuntime:  at android.view.LayoutInflater.rInflate(LayoutInflater.java:806) 
>  04-14 17:53:02.163 15136-15136/? E/AndroidRuntime:  at android.view.LayoutInflater.inflate(LayoutInflater.java:504) 
>  04-14 17:53:02.163 15136-15136/? E/AndroidRuntime:  at android.view.LayoutInflater.inflate(LayoutInflater.java:414) 
>  04-14 17:53:02.163 15136-15136/? E/AndroidRuntime:  at android.view.LayoutInflater.inflate(LayoutInflater.java:365) 
>  04-14 17:53:02.163 15136-15136/? E/AndroidRuntime:  at android.support.v7.app.AppCompatDelegateImplV7.setContentView(AppCompatDelegateImplV7.java:256) 
>  04-14 17:53:02.163 15136-15136/? E/AndroidRuntime:  at android.support.v7.app.AppCompatActivity.setContentView(AppCompatActivity.java:109) 
>  04-14 17:53:02.163 15136-15136/? E/AndroidRuntime:  at com.example.ivylin.corewar.assistantWidgets.WarriorBattleSelfScreen.onCreate(WarriorBattleSelfScreen.java:36) 
>  04-14 17:53:02.163 15136-15136/? E/AndroidRuntime:  at android.app.Activity.performCreate(Activity.java:5933) 
>  04-14 17:53:02.163 15136-15136/? E/AndroidRuntime:  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1105) 
>  04-14 17:53:02.163 15136-15136/? E/AndroidRuntime:  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2251) 
>  04-14 17:53:02.163 15136-15136/? E/AndroidRuntime:  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2360)  
>  04-14 17:53:02.163 15136-15136/? E/AndroidRuntime:  at android.app.ActivityThread.access$800(ActivityThread.java:144)  
>  04-14 17:53:02.163 15136-15136/? E/AndroidRuntime:  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1278)  
>  04-14 17:53:02.163 15136-15136/? E/AndroidRuntime:  at android.os.Handler.dispatchMessage(Handler.java:102)  
>  04-14 17:53:02.163 15136-15136/? E/AndroidRuntime:  at android.os.Looper.loop(Looper.java:135)  
>  04-14 17:53:02.163 15136-15136/? E/AndroidRuntime:  at android.app.ActivityThread.main(ActivityThread.java:5221)  
>  04-14 17:53:02.163 15136-15136/? E/AndroidRuntime:  at java.lang.reflect.Method.invoke(Native Method)  
>  04-14 17:53:02.163 15136-15136/? E/AndroidRuntime:  at java.lang.reflect.Method.invoke(Method.java:372)  
>  04-14 17:53:02.163 15136-15136/? E/AndroidRuntime:  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)  
>  04-14 17:53:02.163 15136-15136/? E/AndroidRuntime:  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)  
>  04-14 17:53:02.163 15136-15136/? E/AndroidRuntime: Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void 
> android.widget.Button.setOnClickListener(android.view.View$OnClickListener)' 
> on a null object reference 
>  04-14 17:53:02.163 15136-15136/? E/AndroidRuntime:  at com.example.ivylin.corewar.assistantWidgets.WarriorBattleFragment.onCreateView(WarriorBattleFragment.java:46) 
>  04-14 17:53:02.163 15136-15136/? E/AndroidRuntime:  at android.app.Fragment.performCreateView(Fragment.java:2053) 
>  04-14 17:53:02.163 15136-15136/? E/AndroidRuntime:  at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:870) 
>  04-14 17:53:02.163 15136-15136/? E/AndroidRuntime:  at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:1045) 
>  04-14 17:53:02.163 15136-15136/? E/AndroidRuntime:  at android.app.FragmentManagerImpl.addFragment(FragmentManager.java:1147) 
>  04-14 17:53:02.163 15136-15136/? E/AndroidRuntime:  at android.app.FragmentManagerImpl.onCreateView(FragmentManager.java:2116) 
>  04-14 17:53:02.163 15136-15136/? E/AndroidRuntime:  at android.app.Activity.onCreateView(Activity.java:5282) 
>  04-14 17:53:02.163 15136-15136/? E/AndroidRuntime:  at android.support.v4.app.BaseFragmentActivityHoneycomb.onCreateView(BaseFragmentActivityHoneycomb.java:34) 
>  04-14 17:53:02.163 15136-15136/? E/AndroidRuntime:  at android.support.v4.app.FragmentActivity.onCreateView(FragmentActivity.java:79) 
>  04-14 17:53:02.163 15136-15136/? E/AndroidRuntime:  at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:733) 
>  04-14 17:53:02.163 15136-15136/? E/AndroidRuntime:  at android.view.LayoutInflater.rInflate(LayoutInflater.java:806)  
>  04-14 17:53:02.163 15136-15136/? E/AndroidRuntime:  at android.view.LayoutInflater.inflate(LayoutInflater.java:504)  
>  04-14 17:53:02.163 15136-15136/? E/AndroidRuntime:  at android.view.LayoutInflater.inflate(LayoutInflater.java:414)  
>  04-14 17:53:02.163 15136-15136/? E/AndroidRuntime:  at android.view.LayoutInflater.inflate(LayoutInflater.java:365)  
>  04-14 17:53:02.163 15136-15136/? E/AndroidRuntime:  at android.support.v7.app.AppCompatDelegateImplV7.setContentView(AppCompatDelegateImplV7.java:256)  
>  04-14 17:53:02.163 15136-15136/? E/AndroidRuntime:  at android.support.v7.app.AppCompatActivity.setContentView(AppCompatActivity.java:109)  
>  04-14 17:53:02.163 15136-15136/? E/AndroidRuntime:  at com.example.ivylin.corewar.assistantWidgets.WarriorBattleSelfScreen.onCreate(WarriorBattleSelfScreen.java:36)  
>  04-14 17:53:02.163 15136-15136/? E/AndroidRuntime:  at android.app.Activity.performCreate(Activity.java:5933)  
>  04-14 17:53:02.163 15136-15136/? E/AndroidRuntime:  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1105)  
>  04-14 17:53:02.163 15136-15136/? E/AndroidRuntime:  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2251)  
>  04-14 17:53:02.163 15136-15136/? E/AndroidRuntime:  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2360)  
>  04-14 17:53:02.163 15136-15136/? E/AndroidRuntime:  at android.app.ActivityThread.access$800(ActivityThread.java:144)  
>  04-14 17:53:02.163 15136-15136/? E/AndroidRuntime:  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1278)  
>  04-14 17:53:02.163 15136-15136/? E/AndroidRuntime:  at android.os.Handler.dispatchMessage(Handler.java:102)  
>  04-14 17:53:02.163 15136-15136/? E/AndroidRuntime:  at android.os.Looper.loop(Looper.java:135)  
>  04-14 17:53:02.163 15136-15136/? E/AndroidRuntime:  at android.app.ActivityThread.main(ActivityThread.java:5221)  
>  04-14 17:53:02.163 15136-15136/? E/AndroidRuntime:  at java.lang.reflect.Method.invoke(Native Method)  
>  04-14 17:53:02.163 15136-15136/? E/AndroidRuntime:  at java.lang.reflect.Method.invoke(Method.java:372)  
>  04-14 17:53:02.163 15136-15136/? E/AndroidRuntime:  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)  
>  04-14 17:53:02.163 15136-15136/? E/AndroidRuntime:  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)

logcat ağırlıklı düğme Bok boş olduğunu söyler gibi görünüyor. Aşağıdaki ayrıntı kodunu görüntüleyin.

Benim Fragment:

public class WarriorBattleFragment extends Fragment implements View.OnClickListener { 
private RecyclerView recyclerView; 
private WarriorBattleAdapter adapter; 

EditText nP1; 
EditText nP2; 
Button bStart; 
static private int click; 

@Override 
public void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
} 

@Override 
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstance) { 
    View layout = inflater.inflate(R.layout.activity_warrior_self_battle_recyclerview, container, false); 
    recyclerView = (RecyclerView) layout.findViewById(R.id.recycler_view); 
    LinearLayoutManager layoutManager; 

    bStart = (Button) recyclerView.findViewById(R.id.bOK); 
    nP1 = (EditText) recyclerView.findViewById(R.id.nP1); 
    nP2 = (EditText) recyclerView.findViewById(R.id.nP2); 
    bStart.setOnClickListener(this); 

    layoutManager = new LinearLayoutManager(getActivity(), LinearLayoutManager.HORIZONTAL, false); 
    recyclerView.setLayoutManager(layoutManager); 
    adapter = new WarriorBattleAdapter(getActivity()); 
    recyclerView.setAdapter(adapter); 
    return layout; 
} 


@Override 
public void onClick(View v) { 
    switch (v.getId()) { 
     case R.id.bStart: 
      if (UserInformation.selectedBW[0].equals("") && UserInformation.selectedBW[1].equals("")) { 
       Toast.makeText(getActivity().getApplicationContext(), "Please Choose A Warrior", Toast.LENGTH_SHORT).show(); 
      } else { 
       click++; 
       if (click == 1) { 
        nP1.setText(UserInformation.selectedBW[0]); 
        adapter.setAdded(1); 
       } else if (click == 2) { 
        bStart.setText("BATTLE!"); 
       } else if (click == 3) { 
        Toast.makeText(getActivity().getApplicationContext(), "WARRIOR FILES UPLOADING", Toast.LENGTH_SHORT).show(); 
       } 
      } 
      if (!UserInformation.selectedBW[0].equals("")) { 
       Intent intent = new Intent(getActivity().getApplicationContext(), DemoDisplay.class); 
       intent.putExtra("wName", UserInformation.selectedBW[0]); 
       intent.putExtra("MODE", UserInformation.selectedBW[0]); 
       startActivity(intent); 

      } else { 
       Toast.makeText(getActivity().getApplicationContext(), "Please select one warrior", Toast.LENGTH_SHORT).show(); 
      } 
      break; 
    } 

} 
}

Benim Etkinlik: Fragment

public class WarriorBattleSelfScreen extends AppCompatActivity implements View.OnClickListener { 
Button bBack; 
Intent intent; 
static int click; 

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    // set to full screen 
    requestWindowFeature(Window.FEATURE_NO_TITLE); 
    getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN); 

    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_warrior_battle_self_screen); 
    bBack = (Button) findViewById(R.id.bBack); 

    // THIS PART IS FOR TEST 
    UserInformation.empty = false; 
    WarriorCardEntity imp = new WarriorCardEntity(); 
    imp.title = "Imp"; 
    imp.image = R.drawable.w9; 
    UserInformation.dataContainer.put(0, imp); 
    WarriorCardEntity rave = new WarriorCardEntity(); 
    rave.title = "Rave"; 
    rave.image = R.drawable.w10; 
    UserInformation.dataContainer.put(1, rave); 
    WarriorCardEntity lin = new WarriorCardEntity(); 
    lin.title = "lin"; 
    lin.image = R.drawable.w20; 
    UserInformation.dataContainer.put(2, lin); 

    bBack.setOnClickListener(this); 
} 

@Override 
public void onClick(View v) { 
    switch (v.getId()) { 
     case R.id.bBack: 
      finish(); 
      break; 
    } 
} 
}

XML:

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    android:layout_width="match_parent" 
    android:layout_height="match_parent" 
    android:screenOrientation="landscape" 
    android:background="@drawable/background_gene"> 

    <fragment class="com.example.ivylin.corewar.assistantWidgets.WarriorBattleFragment" 
     android:id="@+id/b_self_fragment" 
     android:layout_width="match_parent" 
     android:layout_height="320dp" 
     android:layout_centerVertical="true" 
     android:layout_toRightOf="@+id/Add" 
     android:layout_toEndOf="@+id/Add" 
     android:layout_marginLeft="30dp" /> 

    <Button 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:text="Back" 
     android:background="@drawable/button" 
     android:textColor="@color/white" 
     android:id="@+id/bBack" 
     android:layout_marginLeft="33dp" 
     android:layout_marginStart="33dp" 
     android:layout_marginBottom="20dp" 
     android:layout_alignParentBottom="true" 
     android:layout_alignParentLeft="true" 
     android:layout_alignParentStart="true" /> 

</RelativeLayout>

activity_warrior_battle_self_screen aktivitesinden içinde

activity_warrior_self_battle_recyclerview 

<?xml version="1.0" encoding="utf-8"?> 
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    android:layout_width="match_parent" 
    android:layout_height="match_parent" 
    android:fitsSystemWindows="true" 
    android:screenOrientation="landscape" 
    > 

    <RelativeLayout 
     android:layout_width="match_parent" 
     android:layout_height="match_parent" 
     android:layout_centerInParent="true"> 

     <android.support.v7.widget.RecyclerView 
      android:id="@+id/recycler_view" 
      android:layout_width="match_parent" 
      android:layout_height="match_parent" 
      android:layout_alignParentBottom="true"> 
     </android.support.v7.widget.RecyclerView> 


     <TextView 
      android:layout_width="wrap_content" 
      android:layout_height="wrap_content" 
      android:text="P1: " 
      android:textSize="20sp" 
      android:textColor="@color/white" 
      android:id="@+id/tP1" 
      /> 
     <EditText 
      android:layout_width="wrap_content" 
      android:layout_height="wrap_content" 
      android:id="@+id/nP1" 
      android:layout_toRightOf="@+id/tP1" 
      android:hint="WARRIOR1" 
      android:textColor="@color/white" 
      android:textColorHint="@color/white"/> 

     <TextView 
      android:layout_width="wrap_content" 
      android:layout_height="wrap_content" 
      android:text="P2: " 
      android:layout_marginLeft="400dp" 
      android:textSize="20sp" 
      android:textColor="@color/white" 
      android:id="@+id/tP2" 
      /> 
     <EditText 
      android:layout_width="wrap_content" 
      android:layout_height="wrap_content" 
      android:id="@+id/nP2" 
      android:layout_toRightOf="@+id/tP2" 
      android:layout_alignParentRight="true" 
      android:hint="WARRIOR2" 
      android:textColor="@color/white" 
      android:textColorHint="@color/white"/> 

     <Button 
      android:layout_width="wrap_content" 
      android:layout_height="wrap_content" 
      android:text="OK" 
      android:background="@drawable/button" 
      android:textColor="@color/white" 
      android:id="@+id/bOK" 
      android:layout_marginRight="33dp" 
      android:layout_marginEnd="33dp" 
      android:layout_marginBottom="0dp" 
      android:layout_alignParentBottom="true" 
      android:layout_alignParentRight="true" 
      android:layout_alignParentEnd="true" /> 


    </RelativeLayout> 
</RelativeLayout>

XML

kaynak

2016-04-14 Ivy Lin

Bunun yerine kök görünümü demen gerekiyor:

@Override 
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstance) { 
    View layout = inflater.inflate(R.layout.activity_warrior_self_battle_recyclerview, container, false); 
    recyclerView = (RecyclerView) layout.findViewById(R.id.recycler_view); 
    LinearLayoutManager layoutManager; 


    //change to layout.findViewById(): 
    bStart = (Button) layout.findViewById(R.id.bOK); //modified 
    nP1 = (EditText) layout.findViewById(R.id.nP1); //modified 
    nP2 = (EditText) layout.findViewById(R.id.nP2); //modified 
    bStart.setOnClickListener(this); 

    layoutManager = new LinearLayoutManager(getActivity(), LinearLayoutManager.HORIZONTAL, false); 
    recyclerView.setLayoutManager(layoutManager); 
    adapter = new WarriorBattleAdapter(getActivity()); 
    recyclerView.setAdapter(adapter); 
    return layout; 
}

kaynak

2016-04-14 22:49:05

Evet, recyclerView.findViewById(R.id.bOK); numaralı aramanız null değerini döndürüyor. Bunun nedeni, findViewById() numaralı düğmeyi bulmaya çalıştığınız ViewGroup recyclerView'unuzda 'bOK' kimliğine sahip bir düğmenin olmamasıdır.

sizin Düzeni açık olarak

ve anında RecyclerView-etiketi kapatmak: sadece kaza muhtemelen

<android.support.v7.widget.RecyclerView 
    android:id="@+id/recycler_view" 
    android:layout_width="match_parent" 
    android:layout_height="match_parent" 
    android:layout_alignParentBottom="true"> 
</android.support.v7.widget.RecyclerView>

. Böyle düğmenizin sonrasına kadar değil etiketi kapatmalıdır - düğme RecyclerView olmalıdır eğer: Sen RecyclerView üzerinde findViewById() aradığınız

<Button 
      android:layout_width="wrap_content" 
      android:layout_height="wrap_content" 
      android:text="OK" 
      android:background="@drawable/button" 
      android:textColor="@color/white" 
      android:id="@+id/bOK" 
      android:layout_marginRight="33dp" 
      android:layout_marginEnd="33dp" 
      android:layout_marginBottom="0dp" 
      android:layout_alignParentBottom="true" 
      android:layout_alignParentRight="true" 
      android:layout_alignParentEnd="true" /> 

</android.support.v7.widget.RecyclerView>

kaynak

2016-04-14 22:48:20

Sen @Micha tarafından cevaplar göre kodunuzda değişiklik yapmak ve gereken @Daniel

ANCAK

günlükleri tamamen farklı bir sorunu tasvir -

Ayarladığınız senin activity_warrior_self_battle_recyclerview.xml

yılında ebeveyn RelativeLayout için android:screenOrientation="landscape" bağlıyor Ve android:screenOrientationRelativeLayout için geçerli bir android özellik olmadığından bu yanlıştır.

kaynak

2016-04-14 23:07:20

Null Pointer Exception - Android Fragmanı'nda Düğme

cevap

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