iphone - 如何在xcode中的特定时间显示标签

Question

我正在为 iPhone 制作一个 iOS 应用程序，我希望有两个标签在特定时间隐藏并在特定时间显示。就像 Label1 显示在早上 6 点和下午 6 点之间，而 Label2 显示在下午 6 点和早上 6 点之间有什么想法吗？

Answer 1

NSDate *today = [NSDate date];
NSCalendar *gregorian = [[[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar] autorelease];
NSDateComponents *components = [gregorian components:(NSHourCalendarUnit | NSMinuteCalendarUnit | NSSecondCalendarUnit) fromDate:today];

NSInteger hour = [components hour];
NSInteger minute = [components minute];
NSInteger second = [components second];

现在你有时间了，只需添加你的正常逻辑。如果想改变甲酸盐，请这样做......

NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
 [formatter setDateFormat:@"hh:mm a"];
      // another is   [formatter setDateFormat:@"hh:mm:ss"]; 
 NSLog(@"Current Date: %@", [formatter stringFromDate:today]);

Answer 2

[NSDate date];为您提供当前日期。使用 date fromatter 获取您需要的 fromat 并使用setText:方法设置文本。在计时器中触发并设置文本

NSDateFormatter *dateFormatter=[[NSDateFormatter alloc]init];
[dateFormatter setDateFormat:@"EEEE MMMM d, YYYY"];
NSLog(@"%@",[dateFormatter stringFromDate:[NSDate date]]);
[yourLabel setText:[dateFormatter stringFromDate:[NSDate date]]];

编辑

完整代码，试试这个

-(void)showtext
{
    NSDateFormatter *dateFormatter=[[NSDateFormatter alloc]init];
    [dateFormatter setDateFormat:@"hh:mm:ss"];
    NSLog(@"%@",[dateFormatter stringFromDate:[NSDate date]]);
    if(  [self compareTimeIsbetween6])
    {
        [self.date1Label setHidden:NO];
        [self.date2Label setHidden:YES];
      [self.date1Label setText:[dateFormatter stringFromDate:[NSDate date]]];

    }
    else
    {
        [self.date1Label setHidden:YES];
        [self.date2Label setHidden:NO];
        [self.date2Label setText:[dateFormatter stringFromDate:[NSDate date]]];

    }
}

-(BOOL)compareTimeIsbetween6
{
    NSDateComponents *components = [[NSCalendar currentCalendar] components:NSHourCalendarUnit | NSMinuteCalendarUnit | NSSecondCalendarUnit fromDate:[NSDate date]];
    NSInteger currentHour = [components hour];
    NSInteger currentMinute = [components minute];
    NSInteger currentSecond = [components second];

    if (currentHour < 6 || (currentHour > 18 || (currentHour == 18 && (currentMinute > 0 || currentSecond > 0)))) {
        return YES;
    }
    else
    {
        return NO;
    }
}

- (void)viewDidLoad
{
    [super viewDidLoad];

    [NSTimer scheduledTimerWithTimeInterval:1.0 target:self selector:@selector(showtext) userInfo:nil repeats:YES]; // Do any additional setup after loading the view, typically from a nib.
}

。H

@interface ViewController : UIViewController
@property (weak, nonatomic) IBOutlet UILabel *date1Label;
@property (weak, nonatomic) IBOutlet UILabel *date2Label;