iOS中实现简单易懂秒杀倒计时／倒计时代码

示例代码简单易懂：

#import
<uikit uikit.h="">
@interface
viewcontroller : uiviewcontroller
@property
(weak, nonatomic) iboutlet uilabel *daylabel;
@property
(weak, nonatomic) iboutlet uilabel *hourlabel;
@property
(weak, nonatomic) iboutlet uilabel *minutelabel;
@property
(weak, nonatomic) iboutlet uilabel *secondlabel;
@end</uikit>

#import
"viewcontroller.h"
@interface
viewcontroller ()
{
  dispatch_source_t
 _timer;
}
@end
@implementation
viewcontroller
/**
 * 
 获取当天的年月日的字符串
 * 
 这里测试用
 * 
 @return 格式为年-月-日
 */
-(nsstring
 *)getyyyymmdd{
 nsdate
 *now = [nsdate date];
 nsdateformatter
 *formatday = [[nsdateformatter alloc] init];
 formatday.dateformat
 = @"yyyy-mm-dd";
 nsstring
 *daystr = [formatday stringfromdate:now];
 return
daystr;
}
-
 (void)viewdidload
 {
 [super
viewdidload];
 nsdateformatter
 *dateformatter=[[nsdateformatter alloc] init];
 [dateformatter
 setdateformat:@"yyyy-mm-dd"];
 nsdate
 *enddate = [dateformatter datefromstring:[self getyyyymmdd]];
 nsdate
 *enddate_tomorrow = [[nsdate alloc] initwithtimeintervalsincereferencedate:([enddate timeintervalsincereferencedate] +
24*3600)];
 nsdate
 *startdate = [nsdate date];
 nstimeinterval
 timeinterval =[enddate_tomorrow timeintervalsincedate:startdate];
 if
(_timer==nil) {
  __block
int
timeout = timeinterval; //倒计时时间
  if
(timeout!=0)
 {
   dispatch_queue_t
 queue = dispatch_get_global_queue(dispatch_queue_priority_default, 0);
   _timer
 = dispatch_source_create(dispatch_source_type_timer, 0,
0,queue);
   dispatch_source_set_timer(_timer,dispatch_walltime(null,
0),1.0*nsec_per_sec,
0);
//每秒执行
   dispatch_source_set_event_handler(_timer,
 ^{
    if(timeout<=0){
//倒计时结束，关闭
     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);
  }
 }
}
<span
 style="font-family:
 arial, verdana, sans-serif;">效果：</span>

以上所述是小编给大家介绍的ios中实现简单易懂秒杀倒计时／倒计时代码，希望对大家有所帮助