iPhone开发中的技巧整理（二）

1、NSCalendar用法 

-(NSString*) getWeek:(NSDate*)d

{

NSCalendar *calendar = [[NSCalendar alloc]

initWithCalendarIdentifier:NSGregorianCalendar];

unsigned units = NSYearCalendarUnit|NSMonthCalendarUnit|

NSDayCalendarUnit | NSWeekCalendarUnit;

NSDateComponents *components = [calendar components:units

fromDate:d];

[calendar release];

switch([components weekday]) {

case1:

return @"Monday";break;

case2:

return @"Tuesday";break;

case3:

return @"Wednesday";break;

case4:

return @"Thursday";break;

case5:

return @"Friday";break;

case6:

return @"Saturday";break;

case7:

return @"Sunday";break;

default:

return @"NO Week";break;

}

NSLog(@"%@",components); 

}

2、将网络数据读取为字符串

-(NSString*)getDataByURL:(NSString*)url {

return [[NSString alloc]initWithData:[NSData dataWithContentsOfURL: [NSURLURLWithString:[url stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]]] encoding:NSUTF8StringEncoding];

}

3、读取⺴络图⽚

-(UIImage*)getImageByURL:(NSString*)url {

return [[UIImage alloc] initWithData:[NSData dataWithContentsOfURL: [NSURLURLWithString:[url stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]]]];

}

4、多线程(这种方式,只管建立线程,不管回收线程)

[NSThread detachNewThreadSelector:@selector(scheduleTask) toTarget:selfwithObject:nil];

-(void)scheduleTask

{

NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];

[pool release]; 

}

如果有参数,则这么⽤

[NSThread detachNewThreadSelector:@selector(scheduleTask:) toTarget:self withObject:[NSDate date]];

-(void)scheduleTask:(NSDate*)mdate

{

NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];

[pool release];

}

在线程⾥运⾏主线程⾥的⽅法

[self performSelectorOnMainThread:@selector(moveToMain) withObject:nil waitUntilDone:FALSE];

5、⽤户缺省值NSUserDefaults读取:

NSUserDefaults *df = [NSUserDefaults standardUserDefaults];

NSArray *languages = [df objectForKey:@"AppleLanguages"]; 

NSLog(@"all language is %@",languages);

NSLog(@"index is %@",[languages objectAtIndex:0]);

NSLocale *currentLocale = [NSLocale currentLocale];

NSLog(@"language Code is %@",[currentLocale objectForKey:NSLocaleLanguageCode]); 

NSLog(@"Country Code is %@",[currentLocale objectForKey:NSLocaleCountryCode]);

6、view之间转换的动态效果设置

SecondViewController *secondViewController = [[SecondViewController alloc]init];

secondViewController.modalTransitionStyle = UIModalTransitionStyleFlipHorizontal;//水平翻转

[self.navigationController presentModalViewController:secondViewController animated:YES];

[secondViewController release];

7、UIScrollView滑动用法:

-(void)scrollViewDidScroll:(UIScrollView*)scrollView

{

NSLog(@"正在滑动中。。")

}

//⽤户直接滑动UIScrollView,可以看到滑动条

-(void)scrollViewDidEndDelerating:(UIScrollView*)scrollView {

}

//通过其他控件触发UIScrollView滑动,看不到滑动条

-(void)scrollViewDidEndScrollingAnimation:(UIScrollView*)scrollView {

}

//UIScrollView设置滑动不超出本⾝身范围

[scrollViewsetBounces:NO]; 

8、iphone的系统目录:

//得到Document:目录

NSArray*paths =

NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask,YES);

NSString *documentsDirectory = [paths objectAtIndex:0];

//得到temp临时目录

NSString *temPath = NSTemporaryDirectory();

//得到目录上的文件地址

NSString *address = [paths stringByAppendingPathComponent:@"1.rtf"];

9、状态栏显⽰indicator

[UIApplication sharedApplication].networkActivityIndicatorVisible= YES;

10、app Icon显示数字:

- (void)applicationDidEnterBackground:(UIApplication*)application

{

 [[UIApplication sharedApplication] setApplicationIconBadgeNumber:5];

}

11、sqlite保存地址:

NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectoryNSUserDomainMask,YES);

NSString *thePath = [paths objectAtIndex:0];

NSString *filePath = [thePath stringByAppendingPathComponent:@"kilometer.sqlite"];

NSString *dbPath = [[[NSBundle mainBundle] resourcePathstringByAppendingPathComponent:@"kilometer2.sqlite"];

12、键盘弹出隐藏,textfield变位置

_tspasswordTF = [[UITextField alloc] initWithFrame:CGRectMake(100,

150, 260,30)];

_tspasswordTF.backgroundColor= [UIColor redColor];

_tspasswordTF.tag=2;

/*

Use this method to release shared resources, save user data,

_tspasswordTF.delegate=self;

[self.window addSubview:_tspasswordTF];

- (void)textFieldDidBeginEditing:(UITextField*)textField {

[self animateTextField: textField up:YES]; 

}

- (BOOL)textFieldShouldReturn:(UITextField*)textField {

[self animateTextField: textField up:NO]; 

[textField resignFirstResponder];

return YES;

}

- (void) animateTextField: (UITextField*) textField up: (BOOL) up {

const int movementDistance =80; 

// tweak as needed 

const float movementDuration =0.3f; 

// tweak as needed

int movement = (up ? -movementDistance : movementDistance);

[UIView beginAnimations:nil context:nil]; [UIView setAnimationBeginsFromCurrentState:YES]; 

[UIView setAnimationDuration: movementDuration];

self.window.frame=CGRectOffset(self.window.frame,0, movement);

[UIView commitAnimations]; 

}

13、获取图片的尺⼨

CGImageRef img = [imageView.imageCGImage]; 

NSLog(@"%d",CGImageGetWidth(img)); 

NSLog(@"%d",CGImageGetHeight(img));

14、AlertView,ActionSheet的cancelButton点击事件:

- (void)alertView:(UIAlertView*)alertView willDismissWithButtonIndex: (NSInteger)buttonIndex;// before animation and hiding view

{

  NSLog(@"cancel alertView... buttonindex = %d",buttonIndex); //当用户按下Cancel按钮

  if(buttonIndex == [alertViewcancelButtonIndex])

  {

  exit(0); 

  }

}

- (void)actionSheet:(UIActionSheet*)actionSheet didDismissWithButtonIndex:(NSInteger)buttonIndex

{

NSLog(@"%s %d button = %d cancel actionSheet.....",__FUNCTION__,__LINE__, buttonIndex);

//当用户按下Cancel按钮

  if(buttonIndex == [actionSheet cancelButtonIndex]) {

  exit(0);

  } 

}

15、给window设置全局背景图片

self.window.backgroundColor= [UIColor colorWithPatternImage:[UIImage imageNamed:@""]];

16、tabcontroller随意切换tabbar

-(void)tabBarController:(UITabBarController*)tabBarController didSelectViewController:(UIViewController*)viewController 

或者

-(BOOL)tabBarController:(UITabBarController *)tabBarController shouldSelectViewController:(UIViewController *)viewController

或者

_tabBarController.selectedIndex = tabIndex;

17、计算字符串⻓度:

CGFloat w = [title sizeWithFont:[UIFont fontWithName:@"Arial"size: 18]].width;

18、计算点到线段的最短距离

根据结果坐标使⽤用CLLocation类的函数计算实际距离。double

x1, y1, x2, y2, x3, y3;

double px =x2 -x1;

double py = y2 -y1;

double som = px *px + py *py;

double u =((x3 - x1)*px +(y3 - y1)*py)/som;

if(u >1)

{ u=1;}

if (u <0) 

{

u =0;

}

//the closest point

double x = x1 + u *px;

double y= y1 + u * py; 

double dx = x - x3; 

double dy = y - y3;

double dist = sqrt(dx*dx + dy*dy);

19、UISearchBar背景透明 

在使用UISearchBar时,将背景⾊设定为clearColor,或者将translucent设为YES,都

不能使背景透明,经过一番研究,发现了一种超级简单和实用的⽅法:

[[searchbar.subviews objectAtIndex:0] removeFromSuperview];

背景完全消除了,只剩下搜索框本身了。

20、图像与缓存 :

UIImageView *wallpaper = [[UIImageView alloc] initWithImage: [UIImage imageNamed:@"icon.png"]];//会缓存图片

UIImageView *wallpaper = [[UIImageView alloc] initWithImage: [UIImage imageWithContentsOfFile:@"icon.png"]];//不会缓存图⽚片

21、iphone对视图层的操作

// 将textView的边框设置为圆角

_textView.layer.cornerRadius=8;

_textView.layer.masksToBounds=YES;

//给textView添加一个有色边框

_textView.layer.borderWidth=5;

_textView.layer.borderColor= [[UIColor colorWithRed:0.52 green:0.09

blue:0.07 alpha:1] CGColor]; 

//textView添加背景图片

_textView.layer.contents= (id)[UIImage imageNamed:@"31"].CGImage;

22、关闭当前应用

[[UIApplication sharedApplication] performSelector:@selector(terminateWithSuccess)];

23、给iPhone程序添加欢迎界面

1、将你需要的欢迎界面的图片,存成Default.png 

[NSThread sleepForTimeInterval:10.0];这样欢迎页面就停留10秒后消失了。

24、NSString NSDate转换

NSString  *myString = @"testing";

NSData *data = [myString dataUsingEncoding: [NSString defaultCStringEncoding]];

NSString *aStr =

[[NSString alloc] initWithData:aData encoding:NSASCIIStringEncoding];

25、UIWebView中的dataDetectorTypes 

如果你希望在浏览页面时,页面上的电话号码显示成链接形式,点击电话号码就拨打电话,这时你就需要用到dataDetectorTypes了。

NSURL *url = [NSURL URLWithString:@"http://2015.iteye.com"]; 

NSURLRequest *requestObj = [NSURLRequest requestWithURL:url];

webView.dataDetectorTypes=UIDataDetectorTypePhoneNumber; 

[webView loadRequest:requestObj];

26、打开苹果电脑浏览器的代码

如您想在 Mac 软件中集成一键打开浏览器功能,可以使用以下代码

[[NSWorkspace sharedWorkspace] openURLs: urls withAppBundleIdentifier:@"com.apple.Safari"

options: NSWorkspaceLaunchDefault additionalEventParamDescriptor: NULL launchIdentifiers: NULL];

27、设置StatusBar以及NavigationBar的样式

[UIApplication sharedApplication].statusBarStyle=UIStatusBarStyleBlackOpaque;self.navigationController.navigationBar.barStyle = UIBarStyleBlack;

28、隐藏Status Bar你可能知道一个简易的方法,那就是在程序的viewDidLoad中加入以下代码:

[UIApplication sharedApplication].statusBarHidden=YES; 

此法可以隐藏状态条,但问题在于,状态条所占空间依然无法为程序所用。

本篇介绍的方法依然简单,但更为奏效。通过简单的3个步骤,在plist中加入一 个键值来实现。

1.点击程序的Info.plist

2.右键点击任意一处,选择Add Row

3.加入的新键值,命名为UIStatusBarHidden或者Status bar is initially hidden,然后选上这一项。

29、产生随机数的最佳方案

arc4random()会返回一个整型数,因此,返回1至100的随机数可以这样写: 

arc4random()%100 + 1;

30、string和char转换 

NSString*cocoaString = [[NSString alloc] initWithString:@"MyString"];

const char*myCstring = [cocoaString cString];

const char*cString ="Hello";

NSString*cocoString = [[NSString alloc] initWithCString:cString];

31、用UIWebView在当前程序中打开网页如果URL中带中文的话,必须将URL中的中文转成URL形式的才行。

NSString *query = [NSString stringWithFormat:@"http://www.baidu.com?q=苹 果"];

NSString *strUrl = [query stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];

NSURL*url = [NSURL URLWithString:strUrl];

NSURLRequest *requestObj = [NSURLRequest requestWithURL:url]; 

[webView loadRequest:requestObj];

32、阻止ios设备锁屏 

[[UIApplication sharedApplication] setIdleTimerDisabled:YES];

或 

[UIApplication sharedApplication].idleTimerDisabled = YES; 

33、一条命令卸载Xcode和iPhone SDK

sudo /Developer/Library/uninstall-devtools --mode=all

34、获取按钮的title

-(void)btnPressed:(id)sender {

NSString*title = [sender titleForState:UIControlStateNormal]; 

NSString*newText = [[NSString alloc] initWithFormat:@"%@",title]; 

label.text= newText;

[newText release]; 

}

35、NSDate to NSString

NSString *dateStr = [[NSString alloc] initWithFormat:@"%@", date];

或者

NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];

[dateFormatter setDateFormat:@"yyyy-MM-dd HH:mm:ss"];

NSString *strDate = [dateFormatter stringFromDate:[NSDate date]];

NSLog(@"%@", strDate); 

[dateFormatter release];

36、图片由小到大缓慢显示的效果

UIImageView*imageView = [[UIImageView alloc] initWithFrame:CGRectMake(0,0,0,0)];

[imageViewsetImage:[UIImage imageNamed:@"4.jpg"]]; 

self.ANImageView= imageView;

[self.view addSubview:imageView];

[imageView release];

CGContextRef context =UIGraphicsGetCurrentContext(); 

[UIView beginAnimations:nilcontext:context];

[UIView setAnimationCurve:UIViewAnimationCurveEaseInOut]; 

[UIView setAnimationDuration:2.5];

CGImageRef img = [self.ANImageView.imageCGImage];

[ANImageView setFrame:CGRectMake(0,0,CGImageGetWidth(img),CGImageGetHeight(img))];

[UIView commitAnimations]; 

NSLog(@"%lu",CGImageGetWidth(img));

NSLog(@"%lu",CGImageGetHeight(img));

37、数字转字符串

NSString *newText = [[NSString alloc] initWithFormat:@"%d",number]; 

numberlabel.text = newText;

[newText release];

38、随机函数

1、使用26个英文字母随机产生10位的字符串

        int NUMBER_OF_CHARS = 10;

        char data[NUMBER_OF_CHARS];

        for (int x=0;xchar)('A' + (arc4random_uniform(26))));

        NSString *dataPoint = [[NSString alloc] initWithBytes:data length:NUMBER_OF_CHARSencoding:NSUTF8StringEncoding];

2、产生随机数字

 1、arc4random()

（1）、  获取一个随机整数范围在：[0,100)包括0，不包括100

            int x = arc4random() % 100;

（2）、  获取一个随机数范围在：[500,1000），包括500，不包括1000

            int y = (arc4random() % 501) + 500;

（3）、  获取一个随机整数，范围在[from,to），包括from，不包括to

           -(int)getRandomNumber:(int)from to:(int)to

          {

              return (int)(from + (arc4random() % (to – from + 1)));

          }

（4）随机产生浮点数

如果是一位小数：(float)(rand() + 10)/10.0f

如果是两位小数：(float)(rand() + 10)/100.0f

         rand() 是算出0-9的数，+10后就是10-19的数，除10后就是1.0-1.9之间的数了。

2、CCRANDOM_0_1()在cocos2d中使用，范围是[0,1]

使用方法：

float random = CCRANDOM_0_1() * 5;//[0,5] CCRANDOM_O_1()取值范围是[0,1]

3、 random()需要初始化设置种子

srandom((unsigned int)time(time_t*)NULL);初始化时，设置下随机种子就好了。

39、改变键盘颜色的实现

iPhone和iPod touch的键盘颜色其实是可以通过代码更改的,这样能更匹配App的界面风格,下面是改变iPhone键盘颜色的代码。

-(void)textFieldDidBeginEditing:(UITextField*)textField {

NSArray *ws = [[UIApplication sharedApplication] windows]; 

for(UIView *w inws)

{

NSArray *vs = [wsubviews]; 

for(UIView *v invs)

{

if([[NSString stringWithUTF8String:object_getClassName(v)] isEqualToString:@"UIPeripheralHostView"])

{

v.backgroundColor= [UIColor blueColor];

} 

} 

_textField.keyboardAppearance=UIKeyboardAppearanceAlert;//有这个设置属性 才起作用

40、iPhone上实现Default.png动画添加一张和Default.png一样的图片,对这个图片进行动画,从而实现Default动画的渐变消失的效果。

UIImageView *splashView = [[UIImageView alloc]initWithFrame:CGRectMake(0,0,320,480)];

splashView.image= [UIImage imageNamed:@"Default.png"];

[self.window addSubview:splashView];

[self.window bringSubviewToFront:splashView];

[UIView beginAnimations:nilcontext:nil];

[UIView setAnimationDuration:2.0];

[UIView setAnimationTransition:UIViewAnimationTransitionNone forView:

self.window cache:YES];

[UIView setAnimationDelegate:self];

[UIView setAnimationDidStopSelector:@selector(startupAnimationDone:finished:cont ext:)];

splashView.alpha=0.0;

splashView.frame=CGRectMake(-60, -85,440,635);

 [UIView commitAnimations];

41、将EGO主题色添加到xcode中打开终端,执行以下命令

Shell代码

1. mkdir -p ~/Library/Application\ Support/Xcode/Color\ Themes; 2. cd ~/Library/Application\ Support/Xcode/Color\ Themes;

3. curl -O http://developers.enormego.com/assets/egotheme/

EGO.xccolortheme

然后,重启Xcode,选择Preferences > Fonts & Colors,最后从Color Theme 中选择EGO即可。

42、将图片保存到图片库中

-(void)touchesBegan:(NSSet*)touches withEvent:(UIEvent*)event 

{

UITouch*touch = [touches anyObject]; 

if([touch tapCount]==1)

{

UIImageWriteToSavedPhotosAlbum([ANImageViewimage],nil,nil,nil);

UIAlertView*alert = [[UIAlertViewalloc]initWithTitle:@"存储照片

                                              message:@"您已将照⽚存于图片库中,打开照片程序即可查" delegate:self.cancelButtonTitle:@"OK" otherButtonTitles:nil];

[alert show];

[alertrelease];

} 

}

43、读取plist文件

//取得文件路径

NSString *plistPath = [[NSBundle mainBundle] pathForResource:@"文件

名"ofType:@"plist"];

//读取到一个字典

NSDictionary*dictionary = [[NSDictionary alloc] initWithContentsOfFile:plistPath];

//读取到一个数组

NSArray *array = [[NSArray alloc] initWithContentsOfFile:plistPath];

44、使用#pragma mark加上这样的标识后,在导航条上会显示源文件上方法列表,这样就可对功能相关的方法进行分隔,方便查看了。

设置UITabBarController默认的启动Item//a tabBar

UITabBarController *tabBarController = [[UITabBarController alloc]init];

NSArray *controllers = [NSArray arrayWithObjects: nav1, nav2, nav3, nav4,nil];

tabBarController.viewControllers= controllers; tabBarController.selectedViewController= nav2;

45、NSUserDefaults的使用

NSUserDefaults *store = [NSUserDefaults standardUserDefaults]; 

NSUInteger selectedIndex =1;

[storesetInteger:selectedIndexforKey:@"selectedIndex"];

if([store valueForKey:@"selectedIndex"] !=nil) {

NSInteger index = [store integerForKey:@"selectedIndex"]; 

NSLog(@"⽤用户已经设置的selectedIndex的值是:%d", index);

} 

else { 

NSLog(@"请设置默认的值");

}

46、更改Xcode的缺省公司名在终端中执行以下命令:

defaults write com.apple.Xcode PBXCustomTemplateMacroDefiniti ons'{"ORGANIZATIONNAME" = "COMPANY";}'

47、设置uiView,成圆角矩形画个圆角的矩形没啥难的,有两种方法:

1 。直接修改view的样式,系统提供好的了:

view.layer.cornerRadius = 6;

view.layer.masksToBounds = YES; 用layer做就可以了,十分简单。这个需要库 QuartzCore.framework;

2. 在view 里面画圆角矩形 CGFloat radius = 20.0;

CGContextRef context = UIGraphicsGetCurrentContext(); CGContextSetRGBStrokeColor(context, 1.0, 1.0, 1.0, 1);

CGFloat minx = CGRectGetMinX(rect), midx = CGRectGetMidX(rect), maxx =

CGRectGetMaxX(rect);

CGFloat miny = CGRectGetMinY(rect), midy = CGRectGetMidY(rect), maxy =

CGRectGetMaxY(rect);

CGContextMoveToPoint(context, minx, midy); CGContextAddArcToPoint(context, minx, miny, midx, miny, radius); CGContextAddArcToPoint(context, maxx, miny, maxx, midy, radius); CGContextAddArcToPoint(context, maxx, maxy, midx, maxy, radius); CGContextAddArcToPoint(context, minx, maxy, minx, midy, radius); CGContextClosePath(context);

CGContextDrawPath(context, kCGPathFill);

用画笔的方法,在drawRect里面做。

48、画图时图片倒转解决方法

CGContextRef context =UIGraphicsGetCurrentContext();

CGContextSaveGState(context);

CGContextTranslateCTM(context,0,self.bounds.size.height);

CGContextScaleCTM(context,1, -1);

drawImage = [UIImageimageNamed:@"12.jpg"];

CGImageRef image = CGImageRetain(drawImage.CGImage);

CGContextDrawImage(context,CGRectMake(30.0,200,450,695), image);

CGContextRestoreGState(context);

49、Nsstring 自适应文本宽高度

CGSize feelSize = [feeling sizeWithFont:[UIFont systemFontOfSize:12]

constrainedToSize:CGSizeMake(190,200)];

float feelHeight = feelSize.height;

50、用HTTP协议,获取www.baidu.com网站的HTML数据:

[NSString stringWithContentsOfURL:[NSURL URLWithString:@"http://www.baidu.com"]];

51、viewDidLoad中设置按钮图案

UIButton *button = [UIButtonbuttonWithType:UIButtonTypeRoundedRect];

button.frame=CGRectMake(0,0,60,30);

[button addTarget:self action:@selector(buttonAction:)forControlEvents:UIControlEventTouchUpInside];

[self.view addSubview:button];

UIImage *buttonImageNormal = [UIImage imageNamed:@"huifu-001.png"];

UIImage *stretchableButtonImageNormal = [buttonImageNormal

stretchableImageWithLeftCapWidth:12 topCapHeight:0];

 [button setBackgroundImage:stretchableButtonImageNormal forState:UIControlStateNormal];

UIImage *buttonImagePressed = [UIImage imageNamed:@"qyanbuhuifu-001.png"];

UIImage*stretchableButtonImagePressed = [buttonImagePressed stretchableImageWithLeftCapWidth:12 topCapHeight:0]; 

[button setBackgroundImage:stretchableButtonImagePressed forState:UIControlStateHighlighted];

52、键盘上的return键改成Done:

textField.returnKeyType = UIReturnKeyDone;

53、textfield设置成为密码框:

[textField_pwd setSecureTextEntry:YES];

54、收回键盘:

[textField resignFirstResponder]; 

或者 [textfield addTarget:self action:@selector(textFieldDone:) forControlEvents:UIControlEventEditin gDidEndOnExit];

55、振动:

#import<AudioToolbox/AudioToolbox.h>//需加头文件

方法一:AudioServicesPlayAlertSound(kSystemSoundID_Vibrate);

方法二: AudioServicesPlaySystemSound(kSystemSoundID_Vibrate);当设备不支持方法一函数时,起蜂鸣作用,而方法二支持所有设备

56、用Cocoa删除文件:

NSFileManager *defaultManager = [NSFileManager defaultManager]; 

[defaultManager removeFileAtPath: tildeFilename  handler: nil];

57、UIView透明渐变与移动效果:

//动画配制开始

[UIView beginAnimations:@"animation" context:nil]; [UIView setAnimationDuration:2.5];

//图片上升动画

CGRect rect = imgView.frame ;

rect.origin.y = 30;

imgView.frame = rect;

//半透明度渐变动画

imgView.alpha = 0;

//提交动画

[UIView commitAnimations];

58、在UIView的drawRect方法内,用Quartz2D API绘制一个像素宽的水平直线: 

-(void)drawRect:(CGRect)rect{

//获取图形上下文

CGContextRef context = UIGraphicsGetCurrentContext(); //设置图形上下文的路径绘制颜色CGContextSetStrokeColorWithColor(context, [UIColor

whiteColor].CGColor); //取消防锯齿

CGContextSetAllowsAntialiasing(context, NO); //添加线

CGContextMoveToPoint(context, 50, 50); 

CGContextAddLineToPoint(context, 100, 50); //绘制

CGContextDrawPath(context, kCGPathStroke); }

59、用UIWebView加载: www.baidu.com

UIWebView *web = [[UIWebView alloc] initWithFrame:CGRectMake(0, 0, 320, 480)];

[web loadRequest:[NSURLRequest requestWithURL: [NSURL URLWithString:@"http://www.baidu.com"]]];

[self.view addSubview:web]; 

[web release];

60、利用UIImageView实现动画:

- (void)viewDidLoad {

[super viewDidLoad];

UIImageView *fishAni=[[UIImageView alloc] initWithFrame: [[UIScreen mainScreen] bounds]];

[self.view addSubview:fishAni];

 [fishAni release];

//设置动画帧

fishAni.animationImages=[NSArray arrayWithObjects: [UIImage imageNamed:@"1.jpg"],

[UIImage imageNamed:@"2.jpg"],

[UIImage imageNamed:@"3.jpg"],

[UIImage imageNamed:@"4.jpg"],

[UIImage imageNamed:@"5.jpg"],nil ];

//设置动画总时间 fishAni.animationDuration=1.0;

//设置重复次数,0表示不重复 fishAni.animationRepeatCount=0;

//开始动画

[fishAni startAnimating]; }

61、用NSTimer做一个定时器,每隔1秒执行一次pressedDone; 

-(IBAction)clickBtn:(id)sender{

NSTimer *timer = [NSTimer scheduledTimerWithTimeInterval:1 target:self selector:@selector(printHello) userInfo:nil repeats:YES]; 

[timer fire];

 }

62、利用苹果机里的相机进行录像:

-(void) choosePhotoBySourceType: (UIImagePickerControllerCameraCaptureMode) sourceType {

m_imagePickerController = [[[UIImagePickerController alloc] init] autorelease];

m_imagePickerController.modalTransitionStyle = UIModalTransitionStyleCoverVertical;

m_imagePickerController.sourceType = UIImagePickerControllerSourceTypeCamera; m_imagePickerController.cameraDevice =UIImagePickerControllerCameraDeviceFront; 

//m_imagePickerController.cameraCaptureMode =UIImagePickerControllerCameraCaptureModeVideo;

NSArray *sourceTypes = [UIImagePickerController availableMediaTypesForSourceType:m_imagePickerController.sourceType];

if ([sourceTypes containsObject:(NSString *)kUTTypeMovie ]) {

m_imagePickerController.mediaTypes= [NSArray arrayWithObjects: (NSString *)kUTTypeMovie,(NSString *)kUTTypeImage,nil];

}

// m_imagePickerController.cameraCaptureMode = sourceType; //m_imagePickerController.mediaTypes //imagePickerController.allowsEditing = YES;

[self presentModalViewController: m_imagePickerController animated:YES];

 }

-(void) takePhoto {

if ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera])

{

[self choosePhotoBySourceType:nil];

} }

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

- (void)viewDidLoad {

[super viewDidLoad];

UIButton *takePhoto = [UIButton

buttonWithType:UIButtonTypeRoundedRect];

[takePhoto setTitle:@"录像" forState:UIControlStateNormal];

 [takePhoto addTarget:self action:@selector(takePhoto) forControlEvents:UIControlEventTouchUpInside]; 

takePhoto.frame = CGRectMake(50,100,100,30); [self.view addSubview:takePhoto];

}

63、App中调用iPhone的home +电源键截屏功能 

//前置声明是消除警告

CGImageRef UIGetScreenImage();

CGImageRef img = UIGetScreenImage();

UIImage* scImage=[UIImage imageWithCGImage:img]; UIImageWriteToSavedPhotosAlbum(scImage,nil, nil, nil);

64、切割图片的方法

//切割图片

UIImage *image = [UIImage imageNamed:@"7.jpg"];

//设置需要截取的⼤大⼩小

CGRect rect =CGRectMake(20, 50,280,200);

//转换

CGImageRef imageRef = image.CGImage;

//截取函数

CGImageRef imageRefs =CGImageCreateWithImageInRect(imageRef, rect); 

//生成uIImage

UIImage *newImage = [[UIImage alloc] initWithCGImage:imageRefs]; 

//添加到imageView中

imageView= [[UIImageView alloc] initWithImage:newImage]; 

imageView.frame = rect;

65、如何屏蔽父view的touch事件

-(UIView*)hitTest:(CGPoint)point withEvent:(UIEvent*)event

{

CGMutablePathRef path = CGPathCreateMutable();CGPathMoveToPoint(path,NULL,0,0);

CGRect rect =CGRectMake(0,100,320,40);

CGPathAddRect(path,NULL, rect); 

if(CGPathContainsPoint(path,NULL, point,NO)) 

{

[self.superview touchesBegan:nilwithEvent:nil]; 

}

CGPathRelease(path);

return self; 

}

66、用户按home键推送通知

UIApplication *app = [UIApplication sharedApplication]; 

[[NSNotificationCenter defaultCenter]addObserver:self selector:@selector(pressHome:)name:UIApplicationDidEnterBackgroundNotificationobject:app];

-(void)pressHome:(NSNotification*)notification {

NSLog(@"pressHome..."); 

}

67、在UIImageView中旋转图像:

float rotateAngle = M_PI; //M_PI为一角度

CGAffineTransform transform = CGAffineTransformMakeRotation(rotateA ngle);

imageView.transform = transform;

68、隐藏状态栏:

方法一, [UIApplication sharedApplication] setStatusBarHidden:YES animated:NO]; 

方法二, 在应用程序的Info.plist 文件中将 UIStatusBarHidden设置为YES; 

69、构建多个可拖动视图:

@interface DragView: UIImageView{

CGPoint startLocation;

NSString *whichFlower; }

@property (nonatomic ,retain)NSString *whichFlower; 

@end

@implementation DragView

@synthesize whichFlower;

- (void) touchesBegan:(NSSet *)touches withEvent: (UIEvent *)event

{ CGPoint pt = [[touhes anyObject ] locationInView:self]; startLocation = pt;

[[self superview] bringSubviewToFront:self];

}

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

CGPoint pt = [[touches anyObject] locatonInView:self]; CGRect frame = [self frame];

frame.origin.x += pt.x – startLocation.x;

frame.origin.y += pt.y - startLocation.y;

[self setFrame:frame]; }

@end

@interface TestController :UIViewController{

UIView *contentView;

}

@end

@implementation TestController

#define MAXFLOWERS 16

CGPoint randomPoint(){ 

return CGPointMake(random()%6 , random()96);

}

- (void)loadView{

CGRect apprect = [[UIScreen mainScreen] applicationFrame]; 

contentView = [[UIView alloc] initWithFrame :apprect]; 

contentView.backgroundColor = [UIColor blackColor]; 

self.view = contentView;

[contentView release];

for(int i=0 ; i<MAXFLOWERS; i++){

CGRect dragRect = CGRectMake(0.0f ,0.0f, 64.0f ,64.0f); 

dragRect.origin = randomPoint();

DragView *dragger = [[DragView alloc] initWithFrame:dragRect];

 [dragger setUserInteractionEnabled: YES];

NSString *whichFlower = [[NSArray arrayWithObjects:@”blueFlower.png”,@”pinkFlower.png”,nil] objectAtIndex: ( random() %2)];

[dragger setImage:[UIImage imageNamed:whichFlower]]; 

[contentView addSubview :dragger];

[dragger release];

} }

- (void)dealloc{

 [contentView release];

[super dealloc]; 

}

@end

70、iPhone中加入dylib库

加入dylib库时,必须在info中加入头文件路径。/usr/include/库名(不要后缀)

71、iPhone iPad 中App名字如何支持多语言和显示自定义名字

建立InfoPlist.strings,本地化此文件,然后在文件内添加:CFBundleDisplayName = "xxxxxxxxxxx"; //

这样应⽤用程序就能显示成设置的名字“xxxxxxxxxxx”. 

72、在数字键盘上添加button:

//定义一个消息中心

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillShow:) name:UIKeyboardWillShowNotification object:nil]; 

//addObserver:注册一个观察员name:消息名称

- (void)keyboardWillShow:(NSNotification *)note {

// create custom button

UIButton *doneButton = [UIButton buttonWithType:UIButtonTypeCustom];

 doneButton.frame = CGRectMake(0, 163, 106, 53);

[doneButton setImage:[UIImage imageNamed:@"5.png"]

forState:UIControlStateNormal];

[doneButton addTarget:self action:@selector(addRadixPoint) forControlEvents:UIControlEventTouchUpInside];

// locate keyboard view

UIWindow* tempWindow = [[[UIApplication sharedApplication] windows] objectAtIndex:1];

//返回应用程序window

UIView* keyboard;

for(int i=0; i<[tempWindow.subviews count]; i++) 

//遍历window上的所有subview

{

keyboard = [tempWindow.subviews objectAtIndex:i];

// keyboard view found; 

add the custom button to it 

if([[keyboard description] hasPrefix:@"<UIKeyboard"] == YES) 

[keyboard addSubview:doneButton];

} 

}

73、去掉iPhone应用图标上的弧形高光有时候我们的应用程序不需要在图标上加上默认的高光,可以在你的应用的Info.plist中加入:

Icon already includes gloss effects YES

74、实现修改navigation的back按钮 

self.navigationItem.backBarButtonItem=

[[[UIBarButtonItem alloc] initWithTitle:NSLocalizedStringFromTable(@"返回",@"System",nil)style:UIBarButtonItemStyleBordered target:nilaction:nil] autorelease];

75、给图片加上阴影

UIImageView *pageContenterImageView = [[UIImageView alloc]initWithImage: [UIImage imageNamed:@"onePageApple.png"]];

//添加边框

CALayer*layer = [pageContenterImageView layer];

layer.borderColor= [[UIColor whiteColor]CGColor];

layer.borderWidth=0.0f;

//添加四个边阴影

pageContenterImageView.layer.shadowColor= [UIColor blackColor].CGColor;

pageContenterImageView.layer.shadowOffset=CGSizeMake(0,0); pageContenterImageView.layer.shadowOpacity=0.5; pageContenterImageView.layer.shadowRadius=5.0;阴影渲染会严重消耗内存,导致程序咔叽.

/*阴影效果*/

//添加边框

CALayer *layer = [self.pageContenter layer];

layer.borderColor = [[UIColor whiteColor].CGColor];

layer.borderWidth = 0.0f;

//添加四个边阴影

self.pageContenter.layer.shadowColor= [UIColor blackColor].CGColor;//阴影颜色

self.pageContenter.layer.shadowOffset=CGSizeMake(0,0);//阴影偏移self.pageContenter.layer.shadowOpacity=0.5;//阴影不透明度self.pageContenter.layer.shadowRadius=5.0;//阴影半径

二、给视图加上阴影

UIView * content=[[UIViewalloc]initWithFrame:CGRectMake(100,250,503,500)];

content.backgroundColor=[UIColor orangeColor];

content.layer.shadowOffset =CGSizeMake(5,3);

content.layer.shadowOpacity=0.6; 

content.layer.shadowColor = [UIColor blackColor].CGColor;

[self.window addSubview:content]; 

76、UIView有一个属性,clipsTobounds默认情况下是NO,如果,我们想要view2把超出的那部份隐藏起来的话,就得改变它的父视图也就是view1的clipsTobounds属性值。

view1.clipsTobounds = YES;

使用objective-c建立UUIDUUID是128位的值,它可以保证唯一性。通常,它是由机器本身网卡的MAC地

址和当前系统时间来生成的。

UUID是由中划线连接而成的字符串。例如:0A326293-BCDD-4788-8F2D-

C4D8E53C108B

在声明文件中声明一个方法:

#import <UIKit/UIKit.h>

@interfaceUUIDViewController :UIViewController{ }

- (NSString*) createUUID;

@end

对应的实现文件中实现该方法:

- (NSString*) createUUID {

CFUUIDRef uuidObject = CFUUIDCreate(kCFAllocatorDefault);

NSString *uuidStr = (NSString*)CFUUIDCreateString(kCFAllocatorDefault, uuidObject);

CFRelease(uuidObject);

returnuuidStr; }

77、iPhone iPad中横屏显示代码 

1、强制横屏

[application setStatusBarOrientation:UIInterfaceOrientationLandscapeRight animated:NO];

2、在infolist里面加了Supported interface orientations这一项,增加之后添加四个item就是ipad的四个方向

item0 UIInterfaceOrientationLandscapeLeft

item1 UIInterfaceOrientationLandscapeRight 

这表明只支持横屏显示 

78、经常让人混淆迷惑的问题 -数组和其他集合类

当一个对象被添加到一个array, dictionary,或者 set等这样的集合类型中的时候,集合会retain它。对应的,当集合类被release的时候,它会发送对应的release消息给包含在其中的对象。因此,如果你想建立一个包含一堆number的数组,你可以像下面示例中的几个方法来做

NSMutableArray *array; int i;

// ...

for (i = 0; i < 10; i++) {

NSNumber *n = [NSNumber numberWithInt: i];

[array addObject: n]; }

在这种情况下,我们不需要retain这些number,因为array将替我们这么做。

NSMutableArray*array;

int i;

// ...

for (i = 0; i < 10; i++) {

NSNumber*n = [[NSNumber alloc] initWithInt: i];

 [array addObject: n];

[n release];

}

在这个例子中,因为你使用了-alloc去建立了一个number,所以你必须显式的-release它,以保证retain count的平衡。因为将number加入数组的时候,已经retain它了,所以数组中的number变量不会被release

79、UIView动画停止调用方法遇到的问题

在实现UIView的动画的时候,并且使⽤用UIView来重复调⽤用它结束的回调时候要 注意以下方法中的finished参数

-(void)animationDidStop:(NSString *)animationID finished:(NSNumber *)finished context:(void *)context

{

if([finishied boolValue] == YES)

//一定要判断这句话,要不在程序中当多个View刷新的时候,就可能出现动画异常的现象{

//执行想要的动作 }

}

80、判断在UIViewController中,viewWillDisappear的时候是push还是pop出来

- (void)viewWillDisappear:(BOOL)animated

 {

NSArray *viewControllers = self.navigationController.viewControllers;

 if (viewControllers.count > 1 && [viewControllers

objectAtIndex:viewControllers.count-2] == self) {

// View is disappearing because a new view controller was pushed onto the

stack

NSLog(@"New view controller was pushed");

}

 else if ([viewControllers indexOfObject:self] == NSNotFound) 

{ 

// View is disappearing because it was popped from the stack NSLog(@"View controller was popped");

}

 }

81、连接字符串小技巧

NSString*string1 =@"abc / cde";

NSString *string2 =@"abc" @"cde";

NSString*string3 =@"abc" "cde";

NSLog(@"string1 is %@", string1 ); 

NSLog(@"string2 is %@", string2 ); 

NSLog(@"string3 is %@", string3 ); 

打印结果如下:

string1 is abc cde string2 is abccde

82、随文字大小label自适应

label=[[UILabel alloc]initWithFrame:CGRectMake(50,23,175,33)];

label.backgroundColor= [UIColor purpleColor];

[label setFont:[UIFont fontWithName:@"Helvetica"size:30.0]]; 

[label setNumberOfLines:0];

//[myLable setBackgroundColor:[UIColor clearColor]];[self.windowaddSubview:label];

NSString *text = @"this is ok";

UIFont *font = [UIFont fontWithName:@"Helvetica"size:30.0];

CGSize size = [text sizeWithFont: fontconstrainedToSize:CGSizeMake(175.0f,2000.0f)lineBreakMode:UILineBreakModeWordWrap];

CGRect rect=label.frame; 

rect.size= size;

[label setFrame: rect]; 

[label setText: text];

83、UILabel字体加粗

//加粗

lb.font = [UIFont fontWithName:@"Helvetica-Bold"size:20];//加粗并且倾斜

lb.font = [UIFont fontWithName:@"Helvetica-BoldOblique"size:20];

84、为IOS应用组件添加圆角的方法具体的实现是使用QuartzCore库,下面我具体的描述一下实现过程:

• 首先创建一个项目,名字叫:ipad_webwiew

• 利⽤用Interface Builder添加⼀一个UIWebView,然后和相应的代码相关联•添加QuartzCore.framework

代码实现: 头⽂文件:

#import <UIKit/UIKit.h>

#import <QuartzCore/QuartzCore.h>

@interface ipad_webwiewViewController : UIViewController {

IBOutlet UIWebView *myWebView; UIView *myView;

}

@property (nonatomic,retain) UIWebView *myWebView; @end

代码实现:

- (void)viewDidLoad {

[super viewDidLoad]; //给图层添加背景图⽚片://myView.layer.contents = (id)[UIImage

imageNamed:@"view_BG.png"].CGImage; //将图层的边框设置为圆脚

myWebView.layer.cornerRadius = 8; myWebView.layer.masksToBounds = YES; //给图层添加⼀一个有⾊色边框

myWebView.layer.borderWidth = 5; myWebView.layer.borderColor = [[UIColor colorWithRed:0.52

green:0.09 blue:0.07 alpha:1] CGColor]; }

85、实现UIToolBar的自动消失 

-(void)showBar

{

[UIView beginAnimations:nilcontext:nil];

[UIView setAnimationDuration:0.40];

(_toolBar.alpha==0.0) ? (_toolBar.alpha=1.0) : (_toolBar.alpha=0.0);

[UIView commitAnimations];

}

- (void)viewDidAppear:(BOOL)animated {

[NSObject cancelPreviousPerformRequestsWithTarget:self];

[self performSelector:@selector(delayHideBars)withObject:nilafterDelay:3.0];

}

- (void)delayHideBars { [selfshowBar];

}

86、自定义UINavigationItem.rightBarButtonItem

UISegmentedControl *segmentedControl = [[UISegmentedControl alloc]initWithItems:[NSArray arrayWithObjects:@"remote",@"mouse",@"text",nil]];

[segmentedControl insertSegmentWithImage:[UIImage imageNamed:@"home_a.png"] atIndex:0animated:YES];

[segmentedControl insertSegmentWithImage:[UIImage imageNamed:@"myletv_a.png"] atIndex:1animated:YES]; 

segmentedControl.segmentedControlStyle=UISegmentedControlStyleBar; segmentedControl.frame =CGRectMake(0,0,200,30); 

[segmentedControl setMomentary:YES];

[segmentedControl addTarget:selfaction:@selector(segmentAction:)

forControlEvents:UIControlEventValueChanged];

UIBarButtonItem *barButtonItem = [[UIBarButtonItem alloc] initWithCustomView:segmentedControl];

self.navigationItem.rightBarButtonItem= barButtonItem; 

[segmentedControl release];

UINavigationController直接返回到根viewController

 [self.navigationController popToRootViewControllerAnimated:YES];

想要从第五层直接返回到第二层或第三层,用索引的形式

[self.navigationController popToViewController: [self.navigationController.viewControllers objectAtIndex: [self.navigationController.viewControllerscount] -2)]animated:YES];

87、键盘监听事件

#ifdef __IPHONE_5_0

float version = [[[UIDevice currentDevice] systemVersion]floatValue];

if(version >=5.0)

{

[[NSNotificationCenter defaultCenter]addObserver:self

selector:@selector(keyboardWillShow:)name:UIKeyboardWillChangeFrameNotification object:nil];

}

#endif

[[NSNotificationCenter defaultCenter]addObserver:self selector:@selector(keyboardWillShow:)name:UIKeyboardWillShowNotification object:nil];

-(void)keyboardWillShow:(NSNotification *)notification 

{

NSValue *value = [[notification userInfo] objectForKey:@"UIKeyboardFrameEndUserInfoKey"];

CGRect keyboardRect = [value CGRectValue];

 NSLog(@"value %@ %f",value,keyboardRect.size.height); 

[UIView beginAnimations:nilcontext:nil];

[UIView setAnimationDuration:0.25];

keyboardHeight = keyboardRect.size.height;

self.view.frame = CGRectMake(0, -(251- (480-64-

keyboardHeight)),self.view.frame.size.width,self.view.frame.size.height);

[UIView commitAnimations]; 

}

88、 ios6.0强制横屏的方法:

在appDelegate里调用

if (!UIDeviceOrientationIsLandscape([[UIDevice currentDevice] orientation])) {

        [[UIApplication sharedApplication]

setStatusBarOrientation:

UIInterfaceOrientationLandscapeRight animated:NO];

    }