倒计时实现方法

1. 开启定时器，1秒调用一次

- (void)spareTimeRun  {

　　self.timer = [NSTimerscheduledTimerWithTimeInterval:1.0target:selfselector:@selector(timerFireMethod:) userInfo:nilrepeats:YES];

}

 

2. 时间格式转化，用目标时间跟当前时间取得差时间。

-(void)timerFireMethod:(NSTimer*)theTimer {

TuanItemModel *tempGroupProductDic = [self._tuanList objectAtIndex:self.tuanPageIndex];

NSString *string = tempGroupProductDic.endDate;

 

NSDateFormatter *dateformatter =[[[NSDateFormatteralloc]init]autorelease];//定义NSDateFormatter用来显示格式

[dateformatter setDateFormat:@"yyyy-MM-dd HH:mm:ss"];//设定格式

NSDate *todate=[dateformatter dateFromString:string];

NSCalendar *cal = [NSCalendarcurrentCalendar];//定义一个NSCalendar对象

NSDate *today = [NSDate date];//得到当前时间

//用来得到具体的时差

unsignedint unitFlags = NSYearCalendarUnit |NSMonthCalendarUnit | NSDayCalendarUnit | NSHourCalendarUnit |NSMinuteCalendarUnit | NSSecondCalendarUnit;

NSDateComponents *d = [cal components:unitFlags fromDate:today toDate:todate options:0];

self.spareTimeLabel.text = [NSStringstringWithFormat:@"剩余时间%d天%d时%d分%d秒", [d day],[d hour], [d minute], [d second]];

 

//if ([d month]>0) {

//self.spareTimeLabel.text = [NSString stringWithFormat:@"%d月%d日%d时%d分%d秒",[d month], [d day],[d hour], [d minute], [d second]];

//}else {

//self.spareTimeLabel.text = [NSString stringWithFormat:@"%d日%d时%d分%d秒", [d day],[d hour], [d minute], [d second]];

//}

}