NTP协议网络时间同步 ios中应用 实现秒杀倒计时_互联网时间计时

项目中需要实现秒杀倒计时功能，手机客户端本地系统时间有被修改的可能，因此无法获取本地时间来做，下面看实现代码吧

-(void)startTimerShow

{

    self.ysmagTimer = [NSTimer scheduledTimerWithTimeInterval:1.0 target:self selector:@selector(timerFireMethod) userInfo:nil repeats:YES];

}

- (void)timerFireMethod

{

    //当天

    NSDate *todayNet = [NSDate networkDate];

    NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];

    [dateFormatter setDateFormat:@"yyyy-MM-dd HH:mm:ss"];

    [dateFormatter setTimeZone:[NSTimeZone timeZoneWithName:@"CCD"]];

    NSString *destDateString = [dateFormatter stringFromDate:todayNet];

    

    NSTimeInterval interVal = 24*60*60;

    NSDate *tomorrowNet = [todayNet dateByAddingTimeInterval:interVal];

    NSString *destDateStringqq = [dateFormatter stringFromDate:tomorrowNet];

    

    NSString *qgksTime = [NSString stringWithFormat:@"%@-%@-%@ 10:00:00",[destDateStringqq substringWithRange:NSMakeRange(0, 4)],[destDateStringqq substringWithRange:NSMakeRange(5, 2)],[destDateStringqq substringWithRange:NSMakeRange(8, 2)]];

    NSDate *today = [dateFormatter dateFromString:qgksTime];

       NSLog(@"难道就这样成功了吗  %@",today);

   

- (NSString *)intervalFromLastDate: (NSDate *) d1  toTheDate:(NSDate *) d2

{ 

//    NSArray *timeArray1=[dateString1 componentsSeparatedByString:@"."];

//    dateString1=[timeArray1 objectAtIndex:0];

//    

//    

//    NSArray *timeArray2=[dateString2 componentsSeparatedByString:@"."];

//    dateString2=[timeArray2 objectAtIndex:0];

//    

//    NSLog(@"%@.....%@",dateString1,dateString2);

//    NSDateFormatter *date=[[NSDateFormatter alloc] init];

//    [date setDateFormat:@"yyyy-MM-dd HH:mm:ss"];

    

    

//    NSDate *d1=[date dateFromString:dateString1];

    

    NSTimeInterval late1=[d1 timeIntervalSince1970]*1;

    

    

    

//    NSDate *d2=[date dateFromString:dateString2];

    

    NSTimeInterval late2=[d2 timeIntervalSince1970]*1;

    

    

    

    NSTimeInterval cha=late2-late1;

    NSString *timeString=@"";

    NSString *house=@"00";

    NSString *min=@"00";

    NSString *sen=@"00";

    

    sen = [NSString stringWithFormat:@"%d", (int)cha%60];

    //        min = [min substringToIndex:min.length-7];

    //    秒

    sen=[NSString stringWithFormat:@"%@", sen];

    

    

    

    min = [NSString stringWithFormat:@"%d", (int)cha/60%60];

    //        min = [min substringToIndex:min.length-7];

    //    分

    min=[NSString stringWithFormat:@"%@", min];

    

    

    //    小时

    house = [NSString stringWithFormat:@"%d", (int)cha/3600];

    //        house = [house substringToIndex:house.length-7];

    house=[NSString stringWithFormat:@"%@", house];

 

    if ([house intValue]<10) {

        house = [NSString stringWithFormat:@"0%@",house];

    }else{

        house = [NSString stringWithFormat:@"%@",house];

    }

    

    if ([min intValue]<10) {

        min = [NSString stringWithFormat:@"0%@",min];

    }else{

        min = [NSString stringWithFormat:@"%@",min];

    }

    

    if ([sen intValue]<10) {

        sen = [NSString stringWithFormat:@"0%@",sen];

    }else{

        sen = [NSString stringWithFormat:@"%@",sen];

    }

    ytLbl_.text = [house substringWithRange:NSMakeRange(0, 1)];

    atLbl_.text = [house substringWithRange:NSMakeRange(1, 1)];

    ntLbl_.text = [min substringWithRange:NSMakeRange(0, 1)];

    gtLbl_.text = [min substringWithRange:NSMakeRange(1, 1)];

    stLbl_.text = [sen substringWithRange:NSMakeRange(0, 1)];

    htLbl_.text = [sen substringWithRange:NSMakeRange(1, 1)];

    

    timeString=[NSString stringWithFormat:@"%@:%@:%@",house,min,sen];

//    [date release];

    

    

    return timeString;

}