示例代码简单易懂：

#import<uikit uikit.h="">@interfaceViewController : 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"@interfaceViewController (){ dispatch_source_t _timer;}@end@implementationViewController/** * 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]; returndayStr;}- (void)viewDidLoad { [superviewDidLoad]; 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) { __blockinttimeout = 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{ intdays = (int)(timeout/(3600*24)); if(days==0) { self.dayLabel.text = @""; } inthours = (int)((timeout-days*24*3600)/3600); intminute = (int)(timeout-days*24*3600-hours*3600)/60; intsecond = 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，如果大家有任何疑问请给我留言，小编会及时回复大家的。在此也非常感谢大家对网站的支持！