Question

在片段中使用AlarmManager和BroadcastReceiver设置重复警报时遇到实际问题。使用Activity中的以下代码没有问题。当移动到Fragment时，BroadcastReceiver从不调用onReceive。

片段：

public void startAlarm(View view) {

    Log.i(TAG, "startAlarm");

    mAlarmMgr     = (AlarmManager) getActivity().getSystemService(Context.ALARM_SERVICE);
    Intent intent = new Intent(getActivity(), AlarmReceiver.class);
    mAlarmIntent  = PendingIntent.getBroadcast(getActivity(), 0, intent, 0);

    mAlarmMgr.setRepeating(AlarmManager.ELAPSED_REALTIME_WAKEUP,
                           SystemClock.elapsedRealtime(),
                           60 * 1000,
                           mAlarmIntent);
}

public void cancelAlarm(View view) {

    Log.i(TAG, "cancelAlarm");

    // If the alarm has been set, cancel it.
    if (mAlarmMgr!= null) {
        mAlarmMgr.cancel(mAlarmIntent);
    }
}

报警：

public class AlarmReceiver extends BroadcastReceiver {

private static final String TAG = AlarmReceiver.class.getName();

@Override
public void onReceive(Context context, Intent intent) {

    Log.i(TAG, "onReceive");

    // For our recurring task, we'll just display a message
    Toast.makeText(context, "I'm running", Toast.LENGTH_SHORT).show();
}}

清单：

    <receiver android:name=".alarms.AlarmReceiver">
    </receiver>

好奇我可能会出错？我想，也许我没有在Manifest中正确注册接收器。

由于

Answer 1

试试这个，启动alaram

Intent intent = new Intent(getActivity(), Services.class);
Services.shouldContinue=true;
Calendar cal = Calendar.getInstance();
pintent = PendingIntent.getService(getActivity(), 0, intent, 0);
alarm = (AlarmManager) getActivity().getSystemService(Context.ALARM_SERVICE);
if (Services.shouldContinue) {
alarm.setRepeating(AlarmManager.RTC_WAKEUP,cal.getTimeInMillis(), 5 * 1000, pintent);           
 }

取消alaram

   Services.shouldContinue = false;
    if (intent != null) {
        getActivity().stopService(intent);
    }

    alarm.cancel(pintent);

Answer 2

将接收器定义更改为以下

<receiver android:name=".alarms.AlarmReceiver"
            android:enabled="true"
            android:exported="true">

确保拨打startAlarm(View view)来初始化闹钟。

Answer 3

你可能想要的是更像这样的东西

private setRepeatingAlarm(Context context) {
    AlarmManager alarmManager = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
    Intent intent = new Intent(context, AlarmReceiver.class);
    PendingIntent pendingIntent  = PendingIntent.getBroadcast(context, 0, intent, 0);
    long interval = 60 * 1000;
    alarmManager.setInexactRepeating(AlarmManager.RTC_WAKEUP, System.currentTimeMillis(), interval, pendingIntent);
}

这里的主要区别在于使用AlarmManager.RTC_WAKEUP vs AlarmManager.ELAPSED_REALTIME_WAKEUP。

在5.0+警报的最小间隔内应注意的一件事是5分钟。

Android从片段设置警报

3 个答案: