如何在更改按钮时避免闪烁通知更新

Question

我有一个通知,支持播放,前进和后退.

private static Notification createNotification(String interpret, String title, boolean paused) {
//  if (builder == null)
       builder = new NotificationCompat.Builder(context);

    builder.setPriority(Notification.PRIORITY_MAX);
    builder.setAutoCancel(false);
    builder.setContentTitle(title);
    builder.setContentText(interpret);
    builder.setOngoing(true);
    builder.setOnlyAlertOnce(true);
    builder.setSmallIcon(R.drawable.ic_launcher);
    builder.setContentIntent(PendingIntent.getActivity(context, 9, new Intent(context, ApplicationActivity.class), Intent.FLAG_ACTIVITY_BROUGHT_TO_FRONT));
    builder.addAction(R.drawable.av_previous, "", PendingIntent.getBroadcast(context.getApplicationContext(), 0, new Intent(NotificationPlayerControlReceiver.MUSIC_PLAYER_INTENT).putExtra("resultcode", NotificationPlayerControlReceiver.PREVIOUS), PendingIntent.FLAG_CANCEL_CURRENT));

    if (paused)
        builder.addAction(R.drawable.av_play, "", PendingIntent.getBroadcast(context.getApplicationContext(), 2, new Intent(NotificationPlayerControlReceiver.MUSIC_PLAYER_INTENT).putExtra("resultcode", NotificationPlayerControlReceiver.PLAY), PendingIntent.FLAG_CANCEL_CURRENT));
    else
        builder.addAction(R.drawable.av_pause, "", PendingIntent.getBroadcast(context.getApplicationContext(), 3, new Intent(NotificationPlayerControlReceiver.MUSIC_PLAYER_INTENT).putExtra("resultcode", NotificationPlayerControlReceiver.PAUSE), PendingIntent.FLAG_CANCEL_CURRENT));

    builder.addAction(R.drawable.av_next, "", PendingIntent.getBroadcast(context.getApplicationContext(), 1, new Intent(NotificationPlayerControlReceiver.MUSIC_PLAYER_INTENT).putExtra("resultcode", NotificationPlayerControlReceiver.NEXT), PendingIntent.FLAG_CANCEL_CURRENT));

    Notification notification = builder.build();

    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB)
        notification.tickerView = null;

    return notification;
}

更新通知:

 public static void update(String interpret, String title, boolean paused) {
    NotificationManager manager = (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);
    manager.notify(0, createNotification(interpret, title, paused));
}

为了避免在更新时闪烁,我将构建器设置为全局变量,并在每次更新时重复使用它,这非常有用.但重用它,意味着我添加的所有按钮都被重用,并且不可能删除之前添加的操作.

按钮更改只有在每次更新时重新初始化NotificationCompat.Builder时才有效,这意味着我再次闪烁.

如何避免闪烁,但让按钮改变？

编辑:刚刚检查过Rocket Player,他们也没有解决问题,但谷歌播放音乐确实如此

Answer 1

就像鲍里斯所说,问题是每次更新都会建立一个新的通知.我的解决方案涵盖相同的逻辑,但我使用NotificationBuilder...

这是代码:

if (mNotificationBuilder == null) {
            mNotificationBuilder = new NotificationCompat.Builder(this)
                    .setSmallIcon(iconId)
                    .setContentTitle(title)
                    .setContentText(message)
                    .setLargeIcon(largeIcon)
                    .setOngoing(true)
                    .setAutoCancel(false);
        } else {
            mNotificationBuilder.setContentTitle(title)
                    .setContentText(message);
        }

请记住,这mNotificationBuilder是班级中的私人领域.

Answer 2

问题是您每次要更新时都会创建新通知.我遇到了同样的问题,当我做了以下事情时它已修复:

• 在不同的调用之间保留通知的实例createNotification.
• 每次从通知栏中删除此实例时,都将其设置为null.
• 执行以下代码:

码:

private static Notification createNotification(String interpret, String title, boolean paused) {
   if (mNotification == null) {
       // do the normal stuff you do with the notification builder
   } else {
      // set the notification fields in the class member directly
      ... set other fields.
      // The below method is deprecated, but is the only way I have found to set the content title and text
      mNotification.setLatestEventInfo(context, contentTitle, contentText, contentIntent);
   }
   return mNotification;
}

现在当你打电话时notify不会出现闪烁:

manager.notify(0, createNotification(interpret, title, paused));

PS:我还遇到了一个问题,如果我执行setLatestEventInfo了大大小小的图标被淹没了.这就是我做的原因:

int tmpIconResourceIdStore = mNotification.icon;
// this is needed to make the line below not change the large icon of the notification
mNotification.icon = 0;
// The below method is deprecated, but is the only way I have found to set the content title and text
mNotification.setLatestEventInfo(context, contentTitle, contentText, contentIntent);
mNotification.icon = tmpIconResourceIdStore;

查看Adnroid ccode此行mNotification.icon = 0;会禁用图标搞砸.

Answer 3

我知道这是一个相当古老的问题，但由于我没有在其他任何地方找到解决方案，我认为现在回答这个问题可能会帮助其他人解决同样的问题。

这个问题一开始有点棘手。我今天也遇到了，作为我固执的自己，经过一段时间的搜索和尝试，找到了解决方案。

如何解决这个问题呢：

为了与低于 19 的 API 级别兼容，我的解决方案是使用NotificationCompat支持库中的类。

正如其他人所建议的NotificationCompat.Builder那样，只要需要通知，我就会保留对 的引用。我在我的通知中使用的操作仅在最初创建 时添加Builder，而那些将根据情况改变的操作，我也存储在服务的私有成员中。更改后，我会重新使用该Builder对象并NotificationCompat.Action根据我的需要调整该对象。然后我根据 API 级别调用Builder.getNotification()orBuilder.build()方法（由于支持库，可能不需要，但我没有检查。如果我可以省略，请写评论，以便我可以改进我的代码；）

这是我上面刚刚描述的示例代码：

public Notification createForegroundNotification(TaskProgressBean taskProgressBean, boolean indeterminate) {
  Context context = RewardCalculatorApplication.getInstance();

  long maxTime = TaskUtils.getMaxTime(taskEntry);
  long taskElapsedTime = TaskUtils.calculateActualElapsedTime(taskProgressBean);
  long pauseElapsedTime = taskProgressBean.getPauseElapsedTime();

  int pauseToggleActionIcon;
  int pauseToggleActionText;
  PendingIntent pauseToggleActionPI;
  boolean pauseButton = pauseElapsedTime == 0;
  if(pauseButton) {
    pauseToggleActionIcon = R.drawable.ic_stat_av_pause;
    pauseToggleActionText = R.string.btnTaskPause;
    pauseToggleActionPI = getPendingIntentServicePause(context);
  } else {
    pauseToggleActionIcon = R.drawable.ic_stat_av_play_arrow;
    pauseToggleActionText = R.string.btnTaskContinue;
    pauseToggleActionPI = getPendingIntentServiceUnpause(context);
  }

  String contentText = context.getString(R.string.taskForegroundNotificationText,
      TaskUtils.formatTimeForDisplay(taskElapsedTime),
      TaskUtils.formatTimeForDisplay(pauseElapsedTime),
      TaskUtils.formatTimeForDisplay(taskProgressBean.getPauseTotal()));


  // check if we have a builder or not...
  boolean createNotification = foregroundNotificationBuilder == null;
  if(createNotification) { // create one
    foregroundNotificationBuilder = new NotificationCompat.Builder(context);

    // set the data that never changes...plus the pauseAction, because we don't change the
    // pauseAction-object, only it's data...
    pauseAction = new NotificationCompat.Action(pauseToggleActionIcon, getString(pauseToggleActionText), pauseToggleActionPI);
    foregroundNotificationBuilder
        .setContentTitle(taskEntry.getName())
        .setSmallIcon(R.drawable.ic_launcher)
        .setContentIntent(getPendingIntentActivity(context))
        .setOngoing(true)
        .addAction(R.drawable.ic_stat_action_done, getString(R.string.btnTaskFinish), getPendingIntentServiceFinish(context))
        .addAction(pauseAction);
  }

  // this changes with every update
  foregroundNotificationBuilder.setContentText(contentText);

  if(indeterminate) {
    foregroundNotificationBuilder.setProgress(0, 0, true);
  } else {
    foregroundNotificationBuilder.setProgress((int) maxTime, (int) taskElapsedTime, false);
  }

  // if this is not the creation but the button has changed, change the pauseAction's data...
  if(!createNotification && (pauseButton != foregroundNotificationPauseButton)) {
    foregroundNotificationPauseButton = pauseButton;
    pauseAction.icon = pauseToggleActionIcon;
    pauseAction.title = getString(pauseToggleActionText);
    pauseAction.actionIntent = pauseToggleActionPI;
  }

  return (Build.VERSION.SDK_INT < Build.VERSION_CODES.JELLY_BEAN)
         ? foregroundNotificationBuilder.getNotification() // before jelly bean...
         : foregroundNotificationBuilder.build(); // since jelly bean...
}

变量foregroundNotificationBuilder、pauseAction和foregroundNotificationPauseButton是服务类的私有成员。这些getPendingIntent...()方法是简单地创建PendingIntent对象的便捷方法。

然后当我需要使用 更新通知时调用此方法NotificationManager，并将其移交给服务的startForeground()方法。这解决了闪烁和通知中不可更新操作的问题。