抢购、距活动结束，剩余时间倒计时。

/**
 *  倒计时
 *
 *  @param endTime 截止的时间戳
 *
 *  @return 返回的剩余时间
 */
- (NSString*)remainingTimeMethodAction:(long long)endTime
{
    //得到当前时间
    NSDate *nowData = [NSDate date];
    NSDate *endData=[NSDate dateWithTimeIntervalSince1970:endTime];
    NSCalendar* chineseClendar = [ [ NSCalendar alloc ] initWithCalendarIdentifier:NSGregorianCalendar ];
    NSUInteger unitFlags =
    NSHourCalendarUnit | NSMinuteCalendarUnit | NSSecondCalendarUnit | NSDayCalendarUnit | NSMonthCalendarUnit | NSYearCalendarUnit;
    NSDateComponents *cps = [chineseClendar components:unitFlags fromDate:nowData  toDate: endData options:0];
    NSInteger Hour  = [cps hour];
    NSInteger Min   = [cps minute];
    NSInteger Sec   = [cps second];
    NSInteger Day   = [cps day];
    NSInteger Mon   = [cps month];
    NSInteger Year  = [cps year];
        NSLog(  @" From Now to %@, diff: Years: %d  Months: %d, Days; %d, Hours: %d, Mins:%d, sec:%d",
              [nowData description], Year, Mon, Day, Hour, Min,Sec );
    NSString *countdown = [NSString stringWithFormat:@"还剩: %zi天 %zi小时 %zi分钟 %zi秒   ", Day,Hour, Min, Sec];
    if (Sec<0) {
        countdown=[NSString stringWithFormat:@"活动结束/开始抢购"];
    }
    return countdown;
}