Android定时任务相关

    /***
     * Schedule a repeating alarm that has inexact trigger time requirements;
     * for example, an alarm that repeats every hour, but not necessarily at
     * the top of every hour.  These alarms are more power-efficient than
     * the strict recurrences supplied by {@link# setRepeating}, since the
     * system can adjust alarms' phase to cause them to fire simultaneously,
     * avoiding waking the device from sleep more than necessary.
     * 
     * <p>Your alarm's first trigger will not be before the requested time,
     * but it might not occur for almost a full interval after that time.  In
     * addition, while the overall period of the repeating alarm will be as
     * requested, the time between any two successive firings of the alarm
     * may vary.  If your application demands very low jitter, use
     * {@link# setRepeating} instead.
     * 
     * @param type One of ELAPSED_REALTIME, ELAPSED_REALTIME_WAKEUP}, RTC or
     *             RTC_WAKEUP.
     * @param triggerAtTime Time the alarm should first go off, using the
     *                      appropriate clock (depending on the alarm type).  This
     *                      is inexact: the alarm will not fire before this time,
     *                      but there may be a delay of almost an entire alarm
     *                      interval before the first invocation of the alarm.
     * @param interval Interval between subsequent repeats of the alarm.  If
     *                 this is one of INTERVAL_FIFTEEN_MINUTES, INTERVAL_HALF_HOUR,
     *                 INTERVAL_HOUR, INTERVAL_HALF_DAY, or INTERVAL_DAY then the
     *                 alarm will be phase-aligned with other alarms to reduce
     *                 the number of wakeups.  Otherwise, the alarm will be set
     *                 as though the application had called {@link# setRepeating}.
     * @param operation Action to perform when the alarm goes off;
     * typically comes from {@link PendingIntent# getBroadcast
     * IntentSender.getBroadcast()}.
     *
     * @see android.os.Handler
     * @see# set
     * @see# cancel
     * @see android.content.Context# sendBroadcast
     * @see android.content.Context# registerReceiver
     * @see android.content.Intent# filterEquals
     * @see# ELAPSED_REALTIME
     * @see# ELAPSED_REALTIME_WAKEUP
     * @see# RTC
     * @see# RTC_WAKEUP
     * @see# INTERVAL_FIFTEEN_MINUTES
     * @see# INTERVAL_HALF_HOUR
     * @see# INTERVAL_HOUR
     * @see# INTERVAL_HALF_DAY
     * @see# INTERVAL_DAY
     */
    public void setInexactRepeating(int type, long triggerAtTime, long interval,
            PendingIntent operation) {
        try {
            mService.setInexactRepeating(type, triggerAtTime, interval, operation);
        } catch (RemoteException ex) {
        }
    }

/**
     * Alarm time in {@link System# currentTimeMillis System.currentTimeMillis()}
     * (wall clock time in UTC), which will wake up the device when
     * it goes off.
     */
    public static final int RTC_WAKEUP = 0;
    /**
     * Alarm time in {@link System# currentTimeMillis System.currentTimeMillis()}
     * (wall clock time in UTC).  This alarm does not wake the
     * device up; if it goes off while the device is asleep, it will not be
     * delivered until the next time the device wakes up.
     */
    public static final int RTC = 1;
    /**
     * Alarm time in {@link android.os.SystemClock# elapsedRealtime
     * SystemClock.elapsedRealtime()} (time since boot, including sleep),
     * which will wake up the device when it goes off.
     */
    public static final int ELAPSED_REALTIME_WAKEUP = 2;
    /**
     * Alarm time in {@link android.os.SystemClock# elapsedRealtime
     * SystemClock.elapsedRealtime()} (time since boot, including sleep).
     * This alarm does not wake the device up; if it goes off while the device
     * is asleep, it will not be delivered until the next time the device
     * wakes up.
     */
    public static final int ELAPSED_REALTIME = 3;