iphone - 通过计时器更新UILabel不起作用

Question

我正在尝试更新一个UILabel，它从用户的生日倒数到一个较晚的日期。我正在尝试更新标签，以便他们可以看到它递减计数，但似乎无法正常运行。意见表示赞赏!

这是我做计时器的地方:

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view from its nib.
    [NSTimer scheduledTimerWithTimeInterval:1.0 target:self selector:@selector(timeFormatted:) userInfo:nil repeats:NO];
}

这是我获得实际倒数信息的地方...

- (NSString *)timeFormatted:(int)totalSeconds
{       
    NSTimeInterval theTimeInterval = [self numberOfSecondsToLive];

    NSCalendar *sysCalendar = [NSCalendar currentCalendar];

    NSDate *date1 = [[NSDate alloc] init];
    NSDate *date2 = [[NSDate alloc] initWithTimeInterval:theTimeInterval sinceDate:date1]; 

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

    NSDateComponents *conversionInfo = [sysCalendar components:unitFlags fromDate:date1  toDate:date2  options:0];

  _numberofSeconds.text = [NSString stringWithFormat:@" %dyears:%dMonths:%ddays:%dhour:%dminutes:%dseconds",[conversionInfo year],[conversionInfo month], [conversionInfo day], [conversionInfo hour], [conversionInfo minute], [conversionInfo second]];

    [date1 release];
    [date2 release];
 } 

发生的事情是它确实显示了正确的倒计时信息，但是并没有更新它。

先感谢您!

Answer 1

您使用repeats:NO启动了计时器，希望将其设为repeats:YES以使计时器重复。