倒计时时间的处理

private class MainHandler extends Handler {
        @Override
        public void handleMessage(Message msg) {
                        long now = SystemClock.elapsedRealtime();
                        long delta = now - Receiver.ccCall.base;

                        long seconds = (delta + 500) / 1000;  // round to nearest
                        long minutes = seconds / 60;
                        long hours = minutes / 60;
                        long remainderMinutes = minutes - (hours * 60);
                        long remainderSeconds = seconds - (minutes * 60);

                        String secondsString = Long.toString(remainderSeconds);
                        if (secondsString.length() < 2) {
                            secondsString = "0" + secondsString;
                        }
                        String minutesString = Long.toString(remainderMinutes);
                        if (minutesString.length() < 2) {
                            minutesString = "0" + minutesString;
                        }
                        String text = minutesString + ":" + secondsString;
                        if (hours > 0) {
                            String hoursString = Long.toString(hours);
                            if (hoursString.length() < 2) {
                                hoursString = "0" + hoursString;
                            }
                            text = hoursString + ":" + text;
                        }
                        mRecordingTimeView.setText(text);
                                               
                                              mVideoPreview.invalidate();
                        mHandler.sendEmptyMessageDelayed(UPDATE_RECORD_TIME, 1000);
         }
    };