Question

必须每天晚上8点（时钟显示晚上8点）安排活动，无论用户是否跨越不同的时区。以一天的间隔设置重复将不会在正确的时间交付。如何处理？

This是我到目前为止最接近的。

代码段：

private AlarmManager alarmMgr;
private PendingIntent alarmIntent;
...
alarmMgr = (AlarmManager)context.getSystemService(Context.ALARM_SERVICE);
Intent intent = new Intent(context, AlarmReceiver.class);
alarmIntent = PendingIntent.getBroadcast(context, 0, intent, 0);

// Set the alarm to start at 20:00 PM
Calendar calendar = Calendar.getInstance();
calendar.setTimeInMillis(System.currentTimeMillis());
calendar.set(Calendar.HOUR_OF_DAY, 20);
calendar.set(Calendar.MINUTE, 0);

// setRepeating() lets you specify a precise custom interval--in this case,
// 1 day
alarmMgr.setRepeating(AlarmManager.RTC_WAKEUP, calendar.getTimeInMillis(),
        AlarmManager.INTERVAL_DAY, alarmIntent);

Answer 1

要考虑TimeZone次更改，您需要注册一个TIMEZONE_CHANGED广播接收者：

<receiver android:name=".TimeZoneBroadcastReceiver">
    <intent-filter>
        <action android:name="android.intent.action.TIMEZONE_CHANGED " />
    </intent-filter>
</receiver>

我会保存当前TimeZone，然后在下一次警报发生时检索它，这样我们就可以仔细检查是否发生了任何更改，因此java代码将类似于：

public class TimeZoneBroadcastReceiver extends BroadcastReceiver {

    @Override
    public void onReceive(Context context, Intent intent) {
        SharedPreferences pref = PreferenceManager.getDefaultSharedPreferences(context);
        String timeZoneOLD = pref.getString(PREF_TIMEZONE, null);
        String timeZoneNEW = TimeZone.getDefault().getID();   
        long now = System.currentTimeMillis();

        if (timeZoneOLD == null || TimeZone.getTimeZone(timeZoneOLD).getOffset(now) != TimeZone.getTimeZone(timeZoneNEW).getOffset(now)) {
                pref.edit().putString(PREF_TIMEZONE, timeZoneNEW).commit();
                // This means that the TimeZone has changed so we need to update the alarm
                // Set Alarm method goes HERE ...
    }

}

有关如何使用Alarm Manager设置定期任务的更多信息，以下是一个很好的教程：

Android Fundamentals: Scheduling Recurring Tasks

Android使用AlarmManager每天同时设置重复任务

1 个答案: