Сила закрыта при вводе в действие как действие

Question

Я попытался использовать ввод в EditText как действие, но я всегда получаю силу закрытой. Скажите, пожалуйста, где неправильный код из моей программы.

Вот мой код.

noteField = (EditText)findViewById(R.id.noteNote); 
noteField.setOnKeyListener(new View.OnKeyListener() { 
    @Override 
    public boolean onKey(View v, int keyCode, KeyEvent event) { 
     if ((event.getAction() == KeyEvent.ACTION_DOWN) && (keyCode == KeyEvent.KEYCODE_ENTER)){ 
      builder.setTitle("Saved") 
        .setMessage("Confirm saved notes?") 
        .setPositiveButton("Yes", new DialogInterface.OnClickListener() { 
         @Override 
         public void onClick(DialogInterface dialog, int which) { 
          onSaved(); 
         } 
        }) 
        .setNegativeButton("No", new DialogInterface.OnClickListener() { 
         @Override 
         public void onClick(DialogInterface dialog, int which) { 
          finish(); 
         } 
        }) 
        .setNeutralButton("Not yet", new DialogInterface.OnClickListener() { 
         @Override 
         public void onClick(DialogInterface dialog, int which) { 
          dialog.cancel(); 
         } 
        }).setCancelable(true).show(); 
      return true; 
     } 
     return false; 
    } 
}); 

Logcat.

FATAL EXCEPTION: main 
    Process: com.fstudio.kamussakumatematika, PID: 28936 
    java.lang.NullPointerException 
     at com.fstudio.kamussakumatematika.NewNote$1.onKey(NewNote.java:35) 
     at android.view.View.dispatchKeyEvent(View.java:7706) 
     at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:1446) 
     at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:1446) 
     at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:1446) 
     at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:1446) 
     at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:1446) 
     at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:1446) 
     at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:1446) 
     at com.android.internal.policy.impl.PhoneWindow$DecorView.superDispatchKeyEvent(PhoneWindow.java:2076) 
     at com.android.internal.policy.impl.PhoneWindow.superDispatchKeyEvent(PhoneWindow.java:1531) 
     at android.app.Activity.dispatchKeyEvent(Activity.java:2451) 
     at android.support.v7.app.AppCompatActivity.dispatchKeyEvent(AppCompatActivity.java:547) 
     at android.support.v7.view.WindowCallbackWrapper.dispatchKeyEvent(WindowCallbackWrapper.java:59) 
     at android.support.v7.app.AppCompatDelegateImplBase$AppCompatWindowCallbackBase.dispatchKeyEvent(AppCompatDelegateImplBase.java:319) 
     at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchKeyEvent(PhoneWindow.java:2003) 
     at android.view.ViewRootImpl$ViewPostImeInputStage.processKeyEvent(ViewRootImpl.java:4436) 
     at android.view.ViewRootImpl$ViewPostImeInputStage.onProcess(ViewRootImpl.java:4404) 
     at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:3958) 
     at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:4008) 
     at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:3977) 
     at android.view.ViewRootImpl$AsyncInputStage.forward(ViewRootImpl.java:4084) 
     at android.view.ViewRootImpl$InputStage.apply(ViewRootImpl.java:3985) 
     at android.view.ViewRootImpl$AsyncInputStage.apply(ViewRootImpl.java:4141) 
     at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:3958) 
     at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:4008) 
     at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:3977) 
     at android.view.ViewRootImpl$InputStage.apply(ViewRootImpl.java:3985) 
     at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:3958) 
     at android.view.ViewRootImpl.deliverInputEvent(ViewRootImpl.java:6290) 
     at android.view.ViewRootImpl.doProcessInputEvents(ViewRootImpl.java:6253) 
     at android.view.ViewRootImpl.enqueueInputEvent(ViewRootImpl.java:6207) 
     at android.view.ViewRootImpl$ViewRootHandler.handleMessage(ViewRootImpl.java:3744) 
     at android.os.Handler.dispatchMessage(Handler.java:110) 
     at android.os.Looper.loop(Looper.java:193) 
     at android.app.ActivityThread.main(ActivityThread.java:5299) 
     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:825) 
     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:641) 
     at dalvik.system.NativeStart.main(Native Method) 

Answer 1

Инициализируйте AlertDialog.Builder следующим образом, прежде чем использовать его.

@Override 
public boolean onKey(View v, int keyCode, KeyEvent event) { 
    if ((event.getAction() == KeyEvent.ACTION_UP) && (keyCode == KeyEvent.KEYCODE_ENTER)){ 
     AlertDialog.Builder builder = new AlertDialog.Builder(YourActivity.this); 
     ... 
    } 
}