terminer l'activité de non activité

Je suis le développement d'une application. Je veux appeler une boîte de dialogue d'alerte à partir du 1er de l'activité. La boîte de dialogue d'alerte est écrit dans une autre classe qui est un non-activité de la classe. La nécessité de l'application, c'est que la vocation de l'activité devrait se terminer d'alerte qui est écrit en non activité de la classe. Le code de l'appel de l'alerte est comme ci-dessous.

L'appel de l'alerte de la 1ère activité:

public class Activity1 extends Activity {
    /** Called when the activity is first created. */
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.list_layout);
    }//End of onCreate.

        /** Back Button. */
    @Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        if (keyCode == KeyEvent.KEYCODE_BACK) {
            String message = "Do you Want to Exit.";
            Utility.callAlert(message, getApplicationContext());
            return true;
        }
        return super.onKeyDown(keyCode, event);
    }   
}

Et la classe appelée ayant boîte de dialogue d'alerte est :

public class Utility {
    //callAlert method to display alert, when exception occur.
    public static void callAlert(String message, final Context context){
        AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(context);
        alertDialogBuilder.setTitle("MyApplication.");
        alertDialogBuilder.setMessage(message);
        alertDialogBuilder.setNeutralButton("Ok", new DialogInterface.OnClickListener() {                   

            public void onClick(DialogInterface dialog, int which) {
                ((Activity1)context.getApplicationContext()).finish();
            } //end onClick.
        }); //end alertDialog.setButton.
        alertDialogBuilder.show();  
    }
}

Mais cela me donne l'erreur :

02-25 17:00:45.961: D/AndroidRuntime(444): Shutting down VM
02-25 17:00:45.961: W/dalvikvm(444): threadid=1: thread exiting with uncaught exception (group=0x40015560)
02-25 17:00:45.971: E/AndroidRuntime(444): FATAL EXCEPTION: main
02-25 17:00:45.971: E/AndroidRuntime(444): android.view.WindowManager$BadTokenException: Unable to add window -- token null is not for an application
02-25 17:00:45.971: E/AndroidRuntime(444):  at android.view.ViewRoot.setView(ViewRoot.java:531)
02-25 17:00:45.971: E/AndroidRuntime(444):  at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:177)
02-25 17:00:45.971: E/AndroidRuntime(444):  at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:91)
02-25 17:00:45.971: E/AndroidRuntime(444):  at android.app.Dialog.show(Dialog.java:241)
02-25 17:00:45.971: E/AndroidRuntime(444):  at android.app.AlertDialog$Builder.show(AlertDialog.java:802)
02-25 17:00:45.971: E/AndroidRuntime(444):  at com.xxx.myapp.specialclasses.Utility.callAlert(Utility.java:25)
02-25 17:00:45.971: E/AndroidRuntime(444):  at com.xxx.myapp.activities.Activity1.onKeyDown(Activity1.java:149)
02-25 17:00:45.971: E/AndroidRuntime(444):  at android.view.KeyEvent.dispatch(KeyEvent.java:1256)
02-25 17:00:45.971: E/AndroidRuntime(444):  at android.app.Activity.dispatchKeyEvent(Activity.java:2078)
02-25 17:00:45.971: E/AndroidRuntime(444):  at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchKeyEvent(PhoneWindow.java:1663)
02-25 17:00:45.971: E/AndroidRuntime(444):  at android.view.ViewRoot.deliverKeyEventToViewHierarchy(ViewRoot.java:2560)
02-25 17:00:45.971: E/AndroidRuntime(444):  at android.view.ViewRoot.handleFinishedEvent(ViewRoot.java:2535)
02-25 17:00:45.971: E/AndroidRuntime(444):  at android.view.ViewRoot.handleMessage(ViewRoot.java:1867)
02-25 17:00:45.971: E/AndroidRuntime(444):  at android.os.Handler.dispatchMessage(Handler.java:99)
02-25 17:00:45.971: E/AndroidRuntime(444):  at android.os.Looper.loop(Looper.java:123)
02-25 17:00:45.971: E/AndroidRuntime(444):  at android.app.ActivityThread.main(ActivityThread.java:3683)
02-25 17:00:45.971: E/AndroidRuntime(444):  at java.lang.reflect.Method.invokeNative(Native Method)
02-25 17:00:45.971: E/AndroidRuntime(444):  at java.lang.reflect.Method.invoke(Method.java:507)
02-25 17:00:45.971: E/AndroidRuntime(444):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
02-25 17:00:45.971: E/AndroidRuntime(444):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
02-25 17:00:45.971: E/AndroidRuntime(444):  at dalvik.system.NativeStart.main(Native Method)
02-25 17:05:46.061: I/Process(444): Sending signal. PID: 444 SIG: 9

OriginalL'auteur Manoj Fegde | 2013-02-25