很棒的UIKit / Objective-C代码片段

Objective-C iPhone / iPod touch / iPad开发新手，但是我开始发现一些代码如下：

[UIApplication sharedApplication].applicationIconBadgeNumber = 10; 

这将显示在您的应用程序iPhone 10号的独特的红色通知徽章。

请在这里与iPhone / iPod touch / iPad分享您在Objective-C中最喜欢的一两行。 只有PUBLIC API 。

Answer 1

在Safari中打开一个URL

 [[UIApplication sharedApplication] openURL:[NSURL URLWithString:@"http://www.google.com/"]]; 

隐藏状态栏

 [[UIApplication sharedApplication] setStatusBarHidden:YES animated:NO]; 

拨打电话号码（仅限iPhone）

 [[UIApplication sharedApplication] openURL:[NSURL URLWithString:@"tel://9662256888"]]; 

启动Apple Mail

 [[UIApplication sharedApplication] openURL:[NSURL URLWithString:@"mailto://[e-mail]"]]; 

停止响应触摸事件

 [[UIApplication sharedApplication] beginIgnoringInteractionEvents]; 

激活触摸事件

 [[UIApplication sharedApplication] endIgnoringInteractionEvents]; 

显示networking活动指示器

 [UIApplication sharedApplication].networkActivityIndicatorVisible = YES; 

隐藏networking活动指示器

 [UIApplication sharedApplication].networkActivityIndicatorVisible = NO; 

防止iPhone进入睡眠模式

 [UIApplication sharedApplication].idleTimerDisabled = YES; 

Answer 2

1. 显示一个警报窗口：

    UIAlertView* alert = [[[UIAlertView alloc] initWithTitle:@"Warning" message:@"too many alerts" delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil] autorelease]; [alert show] 

2. 获取“文档”文件夹的path：

    NSArray* paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); NSString* documentsDirectory = [paths objectAtIndex:0]; 

3. 将另一个视图控制器推到导航栏上：

    [self.navigationController pushViewController:anotherVC animated:YES]; 

4. 通过将alphaanimation设置为0来淡出UIView：

    [UIView beginAnimations:nil context:NULL]; [UIView setAnimationDuration:1]; // fade away over 1 seconds [aView setAlpha:0]; [UIView commitAnimations]; 

5. 获取应用程序的名称

    self.title = [[[NSBundle mainBundle] infoDictionary] objectForKey:@"CFBundleName"]; 

6. 将状态栏更改为黑色

    [[UIApplication sharedApplication] setStatusBarStyle:UIStatusBarStyleBlackOpaque]; 

7. 更改导航栏的风格（从视图控制器中）：

    self.navigationController.navigationBar.barStyle = UIBarStyleBlack; 

8. 将一个NSString保存到NSUserDefaults中：

    NSUserDefaults* defaults = [NSUserDefaults standardUserDefaults]; [defaults setObject:loginName forKey:kUserLoginName]; 

9. 从NSUserDefaults获取一个NSString：

    NSUserDefaults* defaults = [NSUserDefaults standardUserDefaults]; 

   NSString * loginName = [defaults stringForKey：kUserLoginName];

10. 在调用它之前检查以确保对象支持一种方法：

     if ([item respondsToSelector:@selector(activateBOP:)]) { [item activateBOP:closeBOP]; } 

11. logging类和函数的名称：

     NSLog(@"%s", __PRETTY_FUNCTION__); 

12. 在任何UIView项目（自我）周围添加圆angular和/或边框

     self.layer.borderColor = [UIColor whiteColor]. self.layer.cornerRadius = 8; // rounded corners self.layer.masksToBounds = YES; // prevent drawing outside border 

13. 打开两个纬度/长点之间的方向的Google地图应用程序

     NSString *urlString = [NSString stringWithFormat:@"http://maps.google.com/maps?saddr=%f,%f&daddr=%f,%f&dirflg=d", start.latitude, start.longitude, finish.latitude, finish.longitude]; [[UIApplication sharedApplication] openURL:[NSURL URLWithString:urlString]]; 

Answer 3

将bool保存到用户默认值

 [[NSUserDefaults standardUserDefaults] setBool:YES forKey:@"Yes Bool"]; 

将文件从x复制到y

 [[NSFileManager defaultManager] copyItemAtPath:x toPath:y error:nil]; 

显示一个新的视图

 [self presentModalViewController:(UIViewController *) animated:YES]; 

屏幕触摸方法

 - (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {} 

获取文档目录

 NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); NSString *documentsDirectory = [paths objectAtIndex:0]; 

加载URL

 [MyWebView loadRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:@"http://couleeapps.hostei.com"]]]; 

获取当前date和时间：

 NSCalendar *gregorian = [NSCalendar currentCalendar]; NSDateComponents *dateComponents = [gregorian components:(NSDayCalendarUnit | NSMonthCalendarUnit | NSYearCalendarUnit) fromDate:[NSDate date]]; 

自己的枚举types：

 typedef enum { a = 0, b = 1, c = 2 } enumName; 

石英画弧

 CGContextRef ctxt = UIGraphicsGetCurrentContext(); CGContextAddArc(ctxt, x, y, radius, startDeg, endDeg); 

Answer 4

使设备振动：

 AudioServicesPlaySystemSound(kSystemSoundID_Vibrate); 

使用特定的电话号码打开留言应用程序：

 [[UIApplication sharedApplication] openURL:[NSURL URLWithString:@"sms:123456789"]]; 

停止响应触摸事件：

 [[UIApplication sharedApplication] beginIgnoringInteractionEvents]; 

再次开始回应：

 [[UIApplication sharedApplication] endIgnoringInteractionEvents]; 

最后， 单行代码浏览器 ：

 [[webView mainFrame] loadRequest:[NSURLRequest requestWithURL:[NSURL URLWithString: [urlText stringValue]]]]; 

Answer 5

更改UINavigationView上后退button上的标题。 在推送视图之前，在UINavigationController上使用此代码

 UIBarButtonItem *backBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:@"Back" style: UIBarButtonItemStyleBordered target:nil action:nil]; self.navigationItem.backBarButtonItem = backBarButtonItem; [backBarButtonItem release];