如何更改 AlarmManager 警报？

Question

我在我的应用程序中使用 AlarmManager 在适当的时间设置闹钟。我的应用程序中有多个闹钟，因此每次用户保存闹钟时，我都会找到下次应该播放哪个闹钟，并将该闹钟的 ID 作为意图的额外内容传递。这是我使用的代码：

Intent intent = new Intent(this, AlarmBroadcastReceiver.class);
intent.putExtra("alrmId", finalAlr);
PendingIntent pendingIntent = PendingIntent.getBroadcast(this, 56, intent, 0);
AlarmManager alarmManager = (AlarmManager) getSystemService(ALARM_SERVICE); 
alarmManager.cancel(pendingIntent);
alarmManager.set(AlarmManager.RTC_WAKEUP, (System.currentTimeMillis() + (finalAlrDay * 24 * 60 * 60 * 1000) + (finalAlrHr * 60 * 60 * 1000) + (finalAlrMin * 60 * 1000) + (finalAlrSec * 1000)), pendingIntent);

在这里，如果有任何旧的警报设置，我会取消，然后添加新的警报。所有闹钟都会在正确的时间播放，但问题是我在 intent.putExtra 中设置的 alrmId 值始终与我第一次设置时保持相同。

例如，如果我第一次设置闹钟，当时 alrmId 设置为“1”，那么无论我之后输入什么值，它都将始终保持不变。我尝试对其进行调试，并确保 intent.putExtra("alrmId", FinalAlr) 输入正确的值，因此这不是问题。问题是什么？

Answer 1

在创建 <代码>PendingIntent。

Answer 2

您还可以使用：

final PendingIntent pendingIntent = PendingIntent.getService(
    contextWeakReference.get(),
    0,
    notificationIntent,
    PendingIntent.FLAG_CANCEL_CURRENT
);

正如文档所述：

   /**
     * Flag indicating that if the described PendingIntent already exists,
     * the current one should be canceled before generating a new one.
     * For use with {@link #getActivity}, {@link #getBroadcast}, and
     * {@link #getService}. <p>You can use
     * this to retrieve a new PendingIntent when you are only changing the
     * extra data in the Intent; by canceling the previous pending intent,
     * this ensures that only entities given the new data will be able to
     * launch it.  If this assurance is not an issue, consider
     * {@link #FLAG_UPDATE_CURRENT}.
     */
    public static final int FLAG_CANCEL_CURRENT = 1<<28;


    /**
     * Flag indicating that if the described PendingIntent already exists,
     * then keep it but replace its extra data with what is in this new
     * Intent. For use with {@link #getActivity}, {@link #getBroadcast}, and
     * {@link #getService}. <p>This can be used if you are creating intents where only the
     * extras change, and don't care that any entities that received your
     * previous PendingIntent will be able to launch it with your new
     * extras even if they are not explicitly given to it.
     */
    public static final int FLAG_UPDATE_CURRENT = 1<<27;