【代码笔记】iOS-UILable电子表显示

一，效果图。

二，代码。

RootViewController.h

#import <UIKit/UIKit.h>

@interface RootViewController : UIViewController

{

    UILabel *label;

    NSDateFormatter  *dateFormatter ;

}

@end

RootViewController.m

#import "RootViewController.h"

@interface RootViewController ()

@end

@implementation RootViewController

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil

{

    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];

    if (self) {

        // Custom initialization

    }

    return self;

}

- (void)viewDidLoad

{

    [super viewDidLoad];

    // Do any additional setup after loading the view.

    //label

    label=[[UILabel alloc]initWithFrame:CGRectMake(50, 100, 200, 200)];

    label.backgroundColor=[UIColor redColor];

    [self.view addSubview:label];

    //定时器

    [NSTimer scheduledTimerWithTimeInterval:1.0f target:self selector:@selector(updateTime) userInfo:nil repeats:YES];

    dateFormatter = [[NSDateFormatter alloc] init];

    [dateFormatter setDateFormat:@"HH:mm:ss"];

}

- (void)updateTime

{

    label.text = [dateFormatter stringFromDate:[NSDate date]];

}