IOS關於大型網站搶購、距活動結束，剩餘時間倒計時的實現程式碼，程式碼比較簡單，大家根據需求適當的新增修改刪除程式碼

1.定義4個 Label 來接收倒計時:

@property (weak,nonatomic) IBOutlet UILabel *dayLabel;
@property (weak,nonatomic) IBOutlet UILabel *hourLabel;
@property (weak,nonatomic) IBOutlet UILabel *minuteLabel;
@property (weak,nonatomic) IBOutlet UILabel *secondLabel;

2.在實現檔案中實現方法:

//時間戳轉換為日期格式(毫秒的時間戳)
- (NSString *)timeWithTimeIntervalString:(NSString *)timeString
{
  // 格式化時間
  NSDateFormatter* formatter = [[NSDateFormatter alloc] init];
  formatter.timeZone = [NSTimeZone timeZoneWithName:@"shanghai"];
  [formatter setDateStyle:NSDateFormatterMediumStyle];
  [formatter setTimeStyle:NSDateFormatterShortStyle];
  [formatter setDateFormat:@"yyyy-MM-dd HH:mm:ss"];

  // 毫秒值轉化為秒
  NSDate* date = [NSDate dateWithTimeIntervalSince1970:[timeString doubleValue]/ 1000.0];
  NSString* dateString = [formatter stringFromDate:date];
  NSLog(@"時間 === %@",dateString);
  return dateString;
}
-(void)downSecondHandle:(NSString *)aTimeString{

  NSDateFormatter *dateFormatter=[[NSDateFormatter alloc] init];
  [dateFormatter setDateFormat:@"yyyy-MM-dd HH:mm:ss"];


  NSDate *endDate = [dateFormatter dateFromString:[self timeWithTimeIntervalString:aTimeString]]; //結束時間
  NSDate *endDate_tomorrow = [[NSDate alloc] initWithTimeIntervalSinceReferenceDate:([endDate timeIntervalSinceReferenceDate])];
  NSDate *startDate = [NSDate date];
    NSString* dateString = [dateFormatter stringFromDate:startDate];
  NSLog(@"現在的時間 === %@",dateString);
  NSTimeInterval timeInterval =[endDate_tomorrow timeIntervalSinceDate:startDate];

  if (_timer==nil) {
    __block int timeout = timeInterval; //倒計時時間

    if (timeout!=0) {
      dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT,0);
      _timer = dispatch_source_create(DISPATCH_SOURCE_TYPE_TIMER,queue);
      dispatch_source_set_timer(_timer,dispatch_walltime(NULL,0),1.0*NSEC_PER_SEC,0); //每秒執行
      dispatch_source_set_event_handler(_timer,^{
        if(timeout<=0){ //倒計時結束，關閉
          dispatch_source_cancel(_timer);
          _timer = nil;
          dispatch_async(dispatch_get_main_queue(),^{
            self.dayLabel.text = @"";
            self.hourLabel.text = @"00";
            self.minuteLabel.text = @"00";
            self.secondLabel.text = @"00";
          });
        }else{
          int days = (int)(timeout/(3600*24));
          if (days==0) {
            self.dayLabel.text = @"";
          }
          int hours = (int)((timeout-days*24*3600)/3600);
          int minute = (int)(timeout-days*24*3600-hours*3600)/60;
          int second = timeout-days*24*3600-hours*3600-minute*60;
          dispatch_async(dispatch_get_main_queue(),^{
            if (days==0) {
              self.dayLabel.text = @"0天";
            }else{
              self.dayLabel.text = [NSString stringWithFormat:@"%d天",days];
            }
            if (hours<10) {
              self.hourLabel.text = [NSString stringWithFormat:@"0%d",hours];
            }else{
              self.hourLabel.text = [NSString stringWithFormat:@"%d",hours];
            }
            if (minute<10) {
              self.minuteLabel.text = [NSString stringWithFormat:@"0%d",minute];
            }else{
              self.minuteLabel.text = [NSString stringWithFormat:@"%d",minute];
            }
            if (second<10) {
              self.secondLabel.text = [NSString stringWithFormat:@"0%d",second];
            }else{
              self.secondLabel.text = [NSString stringWithFormat:@"%d",second];
            }

          });
          timeout--;
        }
      });
      dispatch_resume(_timer);
    }
  }


}

3.在需要出使用:

[self downSecondHandle:@"1494622800000"];

以上就是本文的全部內容，希望對大家的學習有所幫助，也希望大家多多支援我們。