获取当前的日期和时间－数码

NSDate* now = [NSDate date];

 NSCalendar *cal = [NSCalendar currentCalendar];

unsigned int unitFlags = NSYearCalendarUnit | NSMonthCalendarUnit | NSDayCalendarUnit | NSHourCalendarUnit | NSMinuteCalendarUnit |NSSecondCalendarUnit;

NSDateComponents *dd = [cal components:unitFlags fromDate:now];

int y = [dd year];

int m = [dd month];

int d = [dd day];

int hour = [dd hour];

int min = [dd minute];

int sec = [dd second];

Lable1.text = [NSString stringWithFormat:@"2d%:2d%:2d%",y,m,d];

Lable2.text =[NSStrinstringWithFormat:@"2d%:2d%:2d%",hour,min,sec];

}

- (void)onTimer {

[viewController updateLabel];

}

在AppDeletate.m文件中增加如下方法：

- (void)applicationDidFinishLaunching:(UIApplication *)application {

timer = [NSTimer scheduledTimerWithTimeInterval:(1.0) target:self selector:@selector(onTimer) userInfo:nil repeats:YES];

    [window addSubview:viewController.view];

[window makeKeyAndVisible];

}