为什么在 Android Studio 中重新创建后通知图标会消失？

Question

以下代码是项目user-interface-samples中关于Notifications的示例代码。

Image A会在我启动BIG_PICTURE_STYLE通知时显示，Image B会在我点击地球图像和通知图标时显示顶部工具栏上的将关闭。

1：如果我点击Image A上的“否”按钮，顶部工具栏上的通知图标将关闭，此通知视图也将关闭。
我很奇怪 BigPictureSocialIntentService.java 中的函数private void handleActionComment(CharSequence comment) 重新创建了通知，为什么通知图标会消失？

2：我修改了BigPictureSocialIntentService.java，你可以看到BigPictureSocialIntentService_Modified.java，然后我点击Image A上的“否”按钮， 我发现通知图标消失了，但是通知视图一直显示，你可以看到Image C，为什么？

顺便说一句，我在 API 30 中对其进行了测试。

MainActivity.java

public class MainActivity extends AppCompatActivity implements AdapterView.OnItemSelectedListener {
 ...  
 private void generateBigPictureStyleNotification() {

        Log.d(TAG, "generateBigPictureStyleNotification()");

        MockDatabase.BigPictureStyleSocialAppData bigPictureStyleSocialAppData =
                MockDatabase.getBigPictureStyleData();        
        String notificationChannelId =
                NotificationUtil.createNotificationChannel(this, bigPictureStyleSocialAppData);
       
        BigPictureStyle bigPictureStyle = new NotificationCompat.BigPictureStyle()
                // Provides the bitmap for the BigPicture notification.
                .bigPicture(
                        BitmapFactory.decodeResource(
                                getResources(),
                                bigPictureStyleSocialAppData.getBigImage()))
                // Overrides ContentTitle in the big form of the template.
                .setBigContentTitle(bigPictureStyleSocialAppData.getBigContentTitle())
                // Summary line after the detail section in the big form of the template.
                .setSummaryText(bigPictureStyleSocialAppData.getSummaryText());

        Intent mainIntent = new Intent(this, BigPictureSocialMainActivity.class);
        TaskStackBuilder stackBuilder = TaskStackBuilder.create(this);     
        stackBuilder.addParentStack(BigPictureSocialMainActivity.class);
        stackBuilder.addNextIntent(mainIntent);
      
        PendingIntent mainPendingIntent =
                PendingIntent.getActivity(
                        this,
                        0,
                        mainIntent,
                        PendingIntent.FLAG_UPDATE_CURRENT
                );
        
        String replyLabel = getString(R.string.reply_label);
        RemoteInput remoteInput =
                new RemoteInput.Builder(BigPictureSocialIntentService.EXTRA_COMMENT)
                        .setLabel(replyLabel)
                        // List of quick response choices for any wearables paired with the phone
                        .setChoices(bigPictureStyleSocialAppData.getPossiblePostResponses())
                        .build();
   
        PendingIntent replyActionPendingIntent;

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
            Intent intent = new Intent(this, BigPictureSocialIntentService.class);
            intent.setAction(BigPictureSocialIntentService.ACTION_COMMENT);
            replyActionPendingIntent = PendingIntent.getService(this, 0, intent, 0);

        } else {
            replyActionPendingIntent = mainPendingIntent;
        }

        NotificationCompat.Action replyAction =
                new NotificationCompat.Action.Builder(
                        R.drawable.ic_reply_white_18dp,
                        replyLabel,
                        replyActionPendingIntent)
                        .addRemoteInput(remoteInput)
                        .build();

     

        NotificationCompat.Builder notificationCompatBuilder =
                new NotificationCompat.Builder(getApplicationContext(), notificationChannelId);

        GlobalNotificationBuilder.setNotificationCompatBuilderInstance(notificationCompatBuilder);

        notificationCompatBuilder
                .setStyle(bigPictureStyle)
                .setContentTitle(bigPictureStyleSocialAppData.getContentTitle())
                .setContentText(bigPictureStyleSocialAppData.getContentText())
                .setSmallIcon(R.drawable.ic_launcher)
                .setLargeIcon(BitmapFactory.decodeResource(
                        getResources(),
                        R.drawable.ic_person_black_48dp))
                .setContentIntent(mainPendingIntent)
                .setDefaults(NotificationCompat.DEFAULT_ALL)
                .setColor(ContextCompat.getColor(getApplicationContext(), R.color.colorPrimary))
                .setSubText(Integer.toString(1))
                .addAction(replyAction)
                .setCategory(Notification.CATEGORY_SOCIAL)
                .setPriority(bigPictureStyleSocialAppData.getPriority())
                .setVisibility(bigPictureStyleSocialAppData.getChannelLockscreenVisibility());

        for (String name : bigPictureStyleSocialAppData.getParticipants()) {
            notificationCompatBuilder.addPerson(name);
        }

        Notification notification = notificationCompatBuilder.build();
        mNotificationManagerCompat.notify(NOTIFICATION_ID, notification);
    }

   ...
}

BigPictureSocialMainActivity.java

public class BigPictureSocialMainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_big_picture_main);

        // Cancel Notification
        NotificationManager notificationManager =
                (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);

        notificationManager.cancel(MainActivity.NOTIFICATION_ID);

        // TODO: Handle and display social post from your database
    }
}

BigPictureSocialIntentService.java

public class BigPictureSocialIntentService extends IntentService {

    private static final String TAG = "BigPictureService";

    public static final String ACTION_COMMENT =
            "com.example.android.wearable.wear.wearnotifications.handlers.action.COMMENT";

    public static final String EXTRA_COMMENT =
            "com.example.android.wearable.wear.wearnotifications.handlers.extra.COMMENT";

    public BigPictureSocialIntentService() {
        super("BigPictureSocialIntentService");
    }

    @Override
    protected void onHandleIntent(Intent intent) {       
        if (intent != null) {
            final String action = intent.getAction();
            if (ACTION_COMMENT.equals(action)) {
                handleActionComment(getMessage(intent));
            }
        }
    }

 
    private void handleActionComment(CharSequence comment) {
        Log.d(TAG, "handleActionComment(): " + comment);

        if (comment != null) {

            // Retrieves NotificationCompat.Builder used to create initial Notification
            NotificationCompat.Builder notificationCompatBuilder =
                    GlobalNotificationBuilder.getNotificationCompatBuilderInstance();

            // Recreate builder from persistent state if app process is killed
            if (notificationCompatBuilder == null) {
                // Note: New builder set globally in the method
                notificationCompatBuilder = recreateBuilderWithBigPictureStyle();
            }

            // Updates active Notification
            Notification updatedNotification = notificationCompatBuilder
                    // Adds a line and comment below content in Notification
                    .setRemoteInputHistory(new CharSequence[]{comment})
                    .build();

            // Pushes out the updated Notification
            NotificationManagerCompat notificationManagerCompat =
                    NotificationManagerCompat.from(getApplicationContext());
            notificationManagerCompat.notify(MainActivity.NOTIFICATION_ID, updatedNotification);
        }
    }


    private CharSequence getMessage(Intent intent) {
        Bundle remoteInput = RemoteInput.getResultsFromIntent(intent);
        if (remoteInput != null) {
            return remoteInput.getCharSequence(EXTRA_COMMENT);
        }
        return null;
    }

    /*
     * This recreates the notification from the persistent state in case the app process was killed.
     * It is basically the same code for creating the Notification from MainActivity.
     */
    private NotificationCompat.Builder recreateBuilderWithBigPictureStyle() {
         ...
    }
}

BigPictureSocialIntentService_Modified.java

public class BigPictureSocialIntentService extends IntentService {
    ....
    private void handleActionComment(CharSequence comment) {
        Log.d(TAG, "handleActionComment(): " + comment);

        if (comment != null) {
           NotificationManager notificationManager =
                    (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);

            notificationManager.cancel(MainActivity.NOTIFICATION_ID);
        }
    }
}

图片 A

图片 B

图片 C

Answer 1

回复操作旨在获取用户回复并将回复显示给用户。因此您无法关闭带有回复操作的通知。

根据android documentation：

处理完文本后，您必须通过调用具有相同 ID 和标签（如果使用）的 NotificationManagerCompat.notify() 来更新通知。这是隐藏直接回复 UI 并向用户确认他们的回复已正确接收和处理的必要条件。

您必须像上一个一样创建另一个通知，并且它不应该有回复动作来告诉用户他/她的回复已收到。

如果你真的想关闭相同ID和标签的通知，你可以创建一个普通的通知并立即关闭。