ToggleButtonでOnCheckedStateListenerを設定しているときのヌルポインタの例外

Question

ToggleButtonでOnCheckedStateListenerを設定しようとしているときに、NULLポインタ例外が発生しました。その例外は何ですか？私はここで

public class AccountViewDetailsFragment extends Fragment { 

ToggleButton toggleButton; 
LinearLayout testLinearLayout; 

public AccountViewDetailsFragment() { 
    // 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.account_view_details_fragment, container, false); 
} 

@Override 
public void onActivityCreated(@Nullable Bundle savedInstanceState) { 
    super.onActivityCreated(savedInstanceState); 

    testLinearLayout = (LinearLayout)getView().findViewById(R.id.toggleTestLinearLayout); 
    toggleButton = (ToggleButton)getView().findViewById(R.id.toggleButtonTest); 


    toggleButton.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() { 
     @Override 
     public void onCheckedChanged(CompoundButton compoundButton, boolean isChecked) { 
      if(isChecked){ 
       testLinearLayout.setVisibility(View.GONE); 
      } 
      if(!isChecked){ 
       testLinearLayout.setVisibility(View.VISIBLE); 
      } 

     } 
    }); 
} 
} 

は、XMLレイアウト

<FrameLayout 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" 
android:background="@color/ivory" 
tools:context="com.cube_me.cubeme.Accounts.AccountViewAttachedFragment"> 

<!-- TODO: Update blank fragment layout --> 

<LinearLayout 
    android:layout_width="match_parent" 
    android:layout_height="wrap_content" 
    android:orientation="vertical"> 

    <ScrollView 
     android:layout_width="match_parent" 
     android:layout_height="wrap_content"> 

     <LinearLayout 
      android:layout_width="match_parent" 
      android:layout_height="wrap_content" 
      android:orientation="vertical"> 

      <LinearLayout 
       android:layout_width="match_parent" 
       android:layout_height="wrap_content" 
       android:orientation="horizontal" 
       android:background="@color/groupBackground"> 

       <TextView 
        android:layout_width="350dp" 
        android:layout_height="@dimen/accountViewDetail_groupTV_height" 
        android:text="Inquiries" 
        android:gravity="start|center" 
        android:paddingLeft="@dimen/accountViewDetail_groupLeftPadding" 
        android:textSize="@dimen/account_groupTextSize" 
        android:textColor="@color/mainText"/> 

       <ToggleButton 
        android:id="@+id/toggleButtonTest" 
        style="@style/myToggle" 
        android:layout_width="20dp" 
        android:layout_height="20dp" 
        android:layout_gravity="center" 
        android:layout_alignParentRight="true" /> 


      </LinearLayout> 
      <LinearLayout 
       android:id="@+id/toggleTestLinearLayout" 
       android:layout_width="match_parent" 
       android:layout_height="wrap_content" 
       android:orientation="horizontal" 
       android:visibility="gone"> 

       <TextView 
        android:id="@+id/account_companyShippingAddressTextView" 
        android:layout_width="@dimen/account_TV_viewWidth" 
        android:layout_height="match_parent" 
        android:background="@color/textViewBackGround" 
        android:gravity="right" 
        android:paddingRight="@dimen/account_TV_rightPadding" 
        android:paddingTop="20dp" 
        android:text="Shipping Address" 
        android:textColor="@color/secondaryText" 
        android:textSize="@dimen/account_secondaryTextSize" /> 

       <LinearLayout 
        android:layout_width="match_parent" 
        android:layout_height="wrap_content" 
        android:orientation="vertical"> 

        <EditText 
         android:id="@+id/account_shippingAddressStreetEditText" 
         android:layout_width="match_parent" 
         android:layout_height="@dimen/account_viewHeight" 
         android:background="@drawable/custom_edittext" 
         android:hint="Street" 
         android:imeOptions="actionNext" 
         android:inputType="text" 
         android:paddingLeft="@dimen/editText_leftPadding" 
         android:textColor="@color/mainText" 
         android:textSize="@dimen/account_mainTextSize" 
         android:theme="@style/EditTextTheme" /> 

        <EditText 
         android:id="@+id/account_shippingAddressBuildingNoEditText" 
         android:layout_width="match_parent" 
         android:layout_height="@dimen/account_viewHeight" 
         android:background="@drawable/custom_edittext" 
         android:hint="Building Number" 
         android:imeOptions="actionNext" 
         android:inputType="text" 
         android:paddingLeft="@dimen/editText_leftPadding" 
         android:textColor="@color/mainText" 
         android:textSize="@dimen/account_mainTextSize" 
         android:theme="@style/EditTextTheme" /> 

        <EditText 
         android:id="@+id/account_shippingAddressCityEditText" 
         android:layout_width="match_parent" 
         android:layout_height="@dimen/account_viewHeight" 
         android:background="@drawable/custom_edittext" 
         android:hint="City" 
         android:imeOptions="actionNext" 
         android:inputType="text" 
         android:paddingLeft="@dimen/editText_leftPadding" 
         android:textColor="@color/mainText" 
         android:textSize="@dimen/account_mainTextSize" 
         android:theme="@style/EditTextTheme" /> 

        <EditText 
         android:id="@+id/account_shippingAddressStateEditText" 
         android:layout_width="match_parent" 
         android:layout_height="@dimen/account_viewHeight" 
         android:background="@drawable/custom_edittext" 
         android:hint="State" 
         android:imeOptions="actionNext" 
         android:inputType="text" 
         android:paddingLeft="@dimen/editText_leftPadding" 
         android:textColor="@color/mainText" 
         android:textSize="@dimen/account_mainTextSize" 
         android:theme="@style/EditTextTheme" /> 

        <EditText 
         android:id="@+id/account_shippingAddressPOBoxEditText" 
         android:layout_width="match_parent" 
         android:layout_height="@dimen/account_viewHeight" 
         android:background="@drawable/custom_edittext" 
         android:hint="PO Box" 
         android:imeOptions="actionNext" 
         android:inputType="text" 
         android:paddingLeft="@dimen/editText_leftPadding" 
         android:textColor="@color/mainText" 
         android:textSize="@dimen/account_mainTextSize" 
         android:theme="@style/EditTextTheme" /> 

        <EditText 
         android:id="@+id/account_shippingAddressPinCodeEditText" 
         android:layout_width="match_parent" 
         android:layout_height="@dimen/account_viewHeight" 
         android:background="@drawable/custom_edittext" 
         android:hint="Pin Code" 
         android:imeOptions="actionNext" 
         android:inputType="text" 
         android:paddingLeft="@dimen/editText_leftPadding" 
         android:textColor="@color/mainText" 
         android:textSize="@dimen/account_mainTextSize" 
         android:theme="@style/EditTextTheme" /> 

        <EditText 
         android:id="@+id/account_shippingAddressCountryEditText" 
         android:layout_width="match_parent" 
         android:layout_height="@dimen/account_viewHeight" 
         android:background="@drawable/custom_edittext" 
         android:hint="Country" 
         android:imeOptions="actionNext" 
         android:inputType="text" 
         android:paddingLeft="@dimen/editText_leftPadding" 
         android:textColor="@color/mainText" 
         android:textSize="@dimen/account_mainTextSize" 
         android:theme="@style/EditTextTheme" /> 
       </LinearLayout> 
      </LinearLayout> 
     </LinearLayout> 
    </ScrollView> 


</LinearLayout> 

..です開発ドキュメントをチェックし、それに応じなかった

FATAL EXCEPTION: main Process: com.cube_me.cubeme, PID: 7869 
                   java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.ToggleButton.setOnClickListener(android.view.View$OnClickListener)' on a null object reference 
                    at com.cube_me.cubeme.Accounts.AccountViewDetailsFragment.onActivityCreated(AccountViewDetailsFragment.java:42) 
                    at android.support.v4.app.Fragment.performActivityCreated(Fragment.java:2083) 
                    at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1129) 
                    at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1286) 
                    at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:758) 
                    at android.support.v4.app.FragmentManagerImpl.execSingleAction(FragmentManager.java:1632) 
                    at android.support.v4.app.BackStackRecord.commitNowAllowingStateLoss(BackStackRecord.java:637) 
                    at android.support.v4.app.FragmentPagerAdapter.finishUpdate(FragmentPagerAdapter.java:143) 
                    at android.support.v4.view.ViewPager.populate(ViewPager.java:1237) 
                    at android.support.v4.view.ViewPager.populate(ViewPager.java:1085) 
                    at android.support.v4.view.ViewPager.onMeasure(ViewPager.java:1611) 
                    at android.view.View.measure(View.java:17547) 
                    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5535) 
                    at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1436) 
                    at android.widget.LinearLayout.measureVertical(LinearLayout.java:722) 
                    at android.widget.LinearLayout.onMeasure(LinearLayout.java:613) 
                    at android.view.View.measure(View.java:17547) 
                    at android.support.v4.widget.DrawerLayout.onMeasure(DrawerLayout.java:1079) 
                    at android.view.View.measure(View.java:17547) 
                    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5535) 
                    at android.widget.FrameLayout.onMeasure(FrameLayout.java:436) 
                    at android.support.v7.widget.ContentFrameLayout.onMeasure(ContentFrameLayout.java:135) 
                    at android.view.View.measure(View.java:17547) 
                    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5535) 
                    at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1436) 
                    at android.widget.LinearLayout.measureVertical(LinearLayout.java:722) 
                    at android.widget.LinearLayout.onMeasure(LinearLayout.java:613) 
                    at android.view.View.measure(View.java:17547) 
                    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5535) 
                    at android.widget.FrameLayout.onMeasure(FrameLayout.java:436) 
                    at android.view.View.measure(View.java:17547) 
                    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5535) 
                    at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1436) 
                    at android.widget.LinearLayout.measureVertical(LinearLayout.java:722) 
                    at android.widget.LinearLayout.onMeasure(LinearLayout.java:613) 
                    at android.view.View.measure(View.java:17547) 
                    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5535) 
                    at android.widget.FrameLayout.onMeasure(FrameLayout.java:436) 
                    at com.android.internal.policy.impl.PhoneWindow$DecorView.onMeasure(PhoneWindow.java:2615) 
                    at android.view.View.measure(View.java:17547) 
                    at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:2015) 
                    at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1173) 
                    at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1379) 
                    at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1061) 
                    at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:5885) 
                    at android.view.Choreographer$CallbackRecord.run(Choreographer.java:767) 
                    at android.view.Choreographer.doCallbacks(Choreographer.java:580) 
                    at android.view.Choreographer.doFrame(Choreographer.java:550) 
                    at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:753) 
                    at android.os.Handler.handleCallback(Handler.java:739) 
                    at android.os.Handler.dispatchMessage(Handler.java:95) 
                    at android.os.Looper.loop(Looper.java:135) 
                    at android.app.ActivityThread.main(ActivityThread.java:5254) 
                    at java.lang.reflect.Method.invoke(Native Method) 
                    at java.lang.reflect.Method.invoke(Method.java:372) 
                   at com.android.internal.o 

Answer 1

を原因となった例外は、あなたがボタンを切り替える初期化する必要があります次のようなOnCreateViewメソッドで：

View view; 
@Override 
public View onCreateView(LayoutInflater inflater, ViewGroup container, 
         Bundle savedInstanceState) { 

    view = inflater.inflate(R.layout.account_view_details_fragment, container, false); 
    toggleButton = (ToggleButton)view.findViewById(R.id.toggleButtonTest); 
    return view; 
}