Iphone 优秀的UIKit/Objective-C代码片段

Objective-C iPhone/iPod touch/iPad开发的新功能，但我开始在一行代码中发现许多强大功能，例如：

[UIApplication sharedApplication].applicationIconBadgeNumber = 10;

它将在你的iphone应用程序上显示一个独特的红色通知徽章，号码为10

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请在这里用Objective-C为iPhone/iPod touch/iPad分享您最喜欢的一行或两行仅限公共API

使设备振动：

AudioServicesPlaySystemSound(kSystemSoundID_Vibrate);

使用特定的电话号码打开Messages应用程序：

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

停止响应触摸事件：

[[UIApplication sharedApplication] beginIgnoringInteractionEvents];

再次开始响应：

[[UIApplication sharedApplication] endIgnoringInteractionEvents];

最后，：

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在Safari中打开URL

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

隐藏状态栏

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

[UIApplication sharedApplication].networkActivityIndicatorVisible = YES;

[UIApplication sharedApplication].networkActivityIndicatorVisible = NO;

拨打电话号码（仅限iPhone）

发布苹果邮件

[[UIApplication sharedApplication] openURL:[NSURL URLWithString:@"mailto://mymail@myserver.com"]];

停止响应触摸事件

[[UIApplication sharedApplication] beginIgnoringInteractionEvents];

[[UIApplication sharedApplication] endIgnoringInteractionEvents];

激活触摸事件

[[UIApplication sharedApplication] beginIgnoringInteractionEvents];

[[UIApplication sharedApplication] endIgnoringInteractionEvents];

显示网络活动指示器

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

[UIApplication sharedApplication].networkActivityIndicatorVisible = YES;

[UIApplication sharedApplication].networkActivityIndicatorVisible = NO;

隐藏网络活动指示器

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

[UIApplication sharedApplication].networkActivityIndicatorVisible = YES;

[UIApplication sharedApplication].networkActivityIndicatorVisible = NO;

防止iPhone进入睡眠模式

[UIApplication sharedApplication].idleTimerDisabled = YES;

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将bool保存为用户默认值

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

将文件从x复制到y

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

显示新视图

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

触摸屏法

- (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"]]];  

获取当前日期和时间：

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

自己的枚举类型：

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

石英引弧

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

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更改UINavigationView上“后退”按钮上的标题。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];

显示警报窗口：

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

获取文档文件夹的路径：

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

将另一个视图控制器推到导航栏上：

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

通过将alpha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];                      

获取应用程序的名称

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

将状态栏更改为黑色

[[UIApplication sharedApplication] setStatusBarStyle:UIStatusBarStyleBlackOpaque];

更改导航栏的样式（从视图控制器中）：

将NSString保存到NSUserDefaults中：

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

NSUserDefaults* defaults = [NSUserDefaults standardUserDefaults];

从NSUserDefaults获取NSString：

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

NSUserDefaults* defaults = [NSUserDefaults standardUserDefaults];

NSString*loginName=[默认值stringForKey:kUserLoginName]

在调用方法之前，请检查以确保对象支持该方法：

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

记录类和函数的名称：

NSLog(@"%s", __PRETTY_FUNCTION__);

在任何UIView项目（自身）周围添加圆角和/或边框

打开谷歌地图应用程序，在两个横向/纵向点之间显示方向

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]]; 

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-[UIAlertView show]

返回

void

。因此，您正在泄漏内存。哎呀，我试图缩短它，结果把它弄糟了。我会修好的，谢谢！没问题！有时候，我希望所有的方法都返回self

self

；然后，我回想起旧的NeXTSTEP代码，并记住为什么不…：）那时候，几乎一个完整的程序可以放在一行：）它是-setBool:forKey:not-setBool:forKey:所以你可能想修复它。