[IOS]iphone之在视图上显示当前的时间,并且时间还在走。

长平狐 发布于 2012/10/25 13:08
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iphone之在视图上显示当前的时间,并且时间还在走。

在RootViewController.h中:

#import <UIKit/UIKit.h>

@interface RootViewController : UIViewController {

NSTimer *_timer;

UILabel *timeLabel;

}

@property (nonatomic,retain) UILabel *timeLabel;

@end

在RootViewController.m中:

#import " RootViewController.h "

#import <stdarg.h>

@implementation RootViewController

@synthesize timeLabel;

-( id)init

{

self = [super init];

if (self) {

}

return self;

}

- ( void)loadView {

UIView *back = [[UIView alloc] initWithFrame:[[UIScreen mainScreen]bounds]];

back.backgroundColor = [UIColor scrollViewTexturedBackgroundColor];

self.view = back;

[back release];

}

// Implement viewDidLoad to do additional setup after loading the view, typically from a nib.

- ( void)viewDidLoad {

[super viewDidLoad];

//

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



// 显示时间

timeLabel = [[UILabel alloc] initWithFrame:CGRectMake( 20, 130, 200, 30)];

timeLabel.backgroundColor = [UIColor clearColor];

[self.view addSubview:timeLabel];

}



// 每一秒都被调用一次

- ( void)timerFunc

{

NSDateFormatter *formatter = [[[NSDateFormatter alloc] init]autorelease];

[formatter setDateFormat: @" MM/dd/YY HH🇲🇲ss "];

NSString *timestamp = [formatter stringFromDate:[NSDate date]];

[timeLabel setText:timestamp]; // 时间在变化的语句

NSLog( @" %@ ",timestamp);

}


此代码用了计数器的原理,

_timer = [NSTimer scheduledTimerWithTimeInterval:1.0f target:self selector:@selector(timerFunc) userInfo:nil repeats:YES]; 每隔1秒调用一下timerFunc方法。 [好好学习,天天向上]


原文链接:http://www.cnblogs.com/iphone520/archive/2011/10/26/2225103.html
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