iPhone開發中的技巧整理(二) – iPhone手機開發技術文章 iPhone軟體開發教學課程

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、將網絡數據讀取為字符串

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

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

}

 

3、讀取⺴絡圖⽚

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

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

}

 

4、多線程(這種方式,隻管建立線程,不管回收線程)

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

-(void)scheduleTask

{

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

[pool release]; 

}

 

如果有參數,則這麼⽤

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

-(void)scheduleTask:(NSDate *)mdate

{

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

[pool release]; }

 

在線程⾥運⾏主線程⾥的⽅法

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

 

5、⽤戶缺省值NSUserDefaults讀取:

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之間轉換的動態效果設置

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

secondViewController.modalTransitionStyle = UIModalTransitionStyleFlipHorizontal;//⽔水平翻轉

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

[secondViewController release];

 

 

7、UIScrollView 滑動用法: -(void)scrollViewDidScroll:(UIScrollView *)scrollView

{

NSLog(@"正在滑動中。。")

}

//⽤戶直接滑動UIScrollView,可以看到滑動條

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

}

//通過其他控件觸發UIScrollView滑動,看不到滑動條

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

}

//UIScrollView 設置滑動不超出本⾝身范圍

[scrollView setBounces:NO]; 

 

8、iphone的系統目錄:

//得到Document:目錄

NSArray *paths =

NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);

NSString *documentsDirectory = [paths objectAtIndex:0];

//得到temp臨時目錄

NSString *temPath = NSTemporaryDirectory();

//得到目錄上的文件地址

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

 

9、狀態欄顯⽰示indicator

[UIApplication sharedApplication].networkActivityIndicatorVisible = YES;

 

10、app Icon顯示數字:

– (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、鍵盤彈出隱藏,textfield變位置

_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、獲取圖片的尺⼨

CGImageRef img = [imageView.image CGImage]; 

NSLog(@"%d",CGImageGetWidth(img)); 

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

 

14、AlertView,ActionSheet的cancelButton點擊事件:

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

{

  NSLog(@"cancel alertView… buttonindex = %d",buttonIndex); //當⽤用戶按下Cancel按鈕

  if (buttonIndex == [alertView cancelButtonIndex]){

  exit(0); 

  }

}

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

{

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

//當⽤用戶按下Cancel按鈕

  if (buttonIndex == [actionSheet cancelButtonIndex]) {

  exit(0);

  } 

}

15、給window設置全局背景圖片

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

 

16、tabcontroller隨意切換tabbar

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

或者

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

或者

_tabBarController.selectedIndex = tabIndex;

 

17、計算字符串⻓度:

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

 

18、計算點到線段的最短距離

根據結果坐標使⽤用CLLocation類的函數計算實際距離。 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時,將背景⾊設定為clearColor,或者將translucent設為YES,都

不能使背景透明,經過一番研究,發現瞭一種超級簡單和實用的⽅法:

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

背景完全消除瞭,隻剩下搜索框本身瞭。

 

20、圖像與緩存 :

UIImageView *wallpaper = [[UIImageView alloc] initWithImage: [UIImage imageNamed:@"icon.png"]]; // 會緩存圖片

UIImageView *wallpaper = [[UIImageView alloc] initWithImage: [UIImage imageWithContentsOfFile:@"icon.png"]]; // 不會緩存圖⽚片

 

21、iphone對視圖層的操作

// 將textView的邊框設置為圓角

_textView.layer.cornerRadius = 8;

_textView.layer.masksToBounds = YES;

//給textView添加一個有色邊框

_textView.layer.borderWidth = 5;

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

blue:0.07 alpha:1] CGColor]; 

//textView添加背景圖片

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

 

22、關閉當前應用

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

 

23、給iPhone程序添加歡迎界面

1、將你需要的歡迎界面的圖片,存成Default.png 

[NSThread sleepForTimeInterval:10.0]; 這樣歡迎頁面就停留10秒後消失瞭。

 

24、NSString NSDate轉換

NSString* myString= @"testing";

NSData* data=[myString dataUsingEncoding: [NSString defaultCStringEncodi ng]];

NSString* aStr =

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

 

25、UIWebView中的dataDetectorTypes 

如果你希望在瀏覽頁面時,頁面上的電話號碼顯示成鏈接形式,點擊電話號碼就撥打電話,這時你就需要用到dataDetectorTypes瞭。

 

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

NSURLRequest *requestObj = [NSURLRequest requestWithURL:url]; webView.dataDetectorTypes = UIDataDetectorTypePhoneNumber; 

[webView loadRequest:requestObj];

 

26、打開蘋果電腦瀏覽器的代碼

如您想在 Mac 軟件中集成一鍵打開瀏覽器功能,可以使用以下代碼

 

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

options: NSWorkspaceLaunchDefault additionalEventParamDescriptor: NULL launchIdentifiers: NULL];

 

27、設置StatusBar以及NavigationBar的樣式

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

 

28、隱藏Status Bar 你可能知道一個簡易的方法,那就是在程序的viewDidLoad中加入以下代碼:

 

[UIApplication sharedApplication].statusBarHidden = YES; 

此法可以隱藏狀態條,但問題在於,狀態條所占空間依然無法為程序所用。

本篇介紹的方法依然簡單,但更為奏效。通過簡單的3個步驟,在plist中加入一 個鍵值來實現。

1. 點擊程序的Info.plist

2. 右鍵點擊任意一處,選擇Add Row

3. 加入的新鍵值,命名為UIStatusBarHidden或者Status bar is initially hidden,然後選上這一項。

 

29、產生隨機數的最佳方案

arc4random()會返回一個整型數,因此,返回1至100的隨機數可以這樣寫: 

arc4random()%100 + 1;

 

30、string 和char轉換 

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

const char *myCstring = [cocoaString cString];

const char *cString = "Hello";

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

 

31、用UIWebView在當前程序中打開網頁 如果URL中帶中文的話,必須將URL中的中文轉成URL形式的才行。

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

NSString *strUrl = [query stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];

NSURL *url = [NSURL URLWithString:strUrl];

NSURLRequest *requestObj = [NSURLRequest requestWithURL:url]; 

[webView loadRequest:requestObj];

 

32、阻止ios設備鎖屏 

[[UIApplication sharedApplication] setIdleTimerDisabled:YES];

或 

[UIApplication sharedApplication].idleTimerDisabled = YES; 

 

33、一條命令卸載Xcode和 iPhone SDK

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

 

34、獲取按鈕的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、圖片由小到大緩慢顯示的效果

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

[imageView setImage:[UIImage imageNamed:@"4.jpg"]]; 

self.ANImageView = imageView;

[self.view addSubview:imageView];

[imageView release];

CGContextRef context = UIGraphicsGetCurrentContext(); 

[UIView beginAnimations:nil context:context];

[UIView setAnimationCurve:UIViewAnimationCurveEaseInOut]; 

[UIView setAnimationDuration:2.5];

CGImageRef img = [self.ANImageView.image CGImage];

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

[UIView commitAnimations]; 

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

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

 

37、數字轉字符串

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

numberlabel.text = newText;

[newText release];

 

38、隨機函數arc4random() 的使用.

在iPhone中,RAND_MAX是0x7fffffff (2147483647),而arc4random()返回的 最大值則是 0x100000000 (4294967296),從而有更好的精度。使用 arc4random()還不需要生成隨機種子,因為第一次調用的時候就會自動生成。

如:

arc4random() 來獲取0到100之間浮點數

#define ARC4RANDOM_MAX 0x100000000

double val = floorf(((double)arc4random() / ARC4RANDOM_MAX) * 100.0f);

1. self.view.backgroundColor = [UIColor colorWithHue: arc4random() % 2 55 / 255

2. 3. 4.

saturation: arc4random() % 2 brightness: arc4random() % 2

alpha: 1.0];

 

39、改變鍵盤顏色的實現

iPhone和iPod touch的鍵盤顏色其實是可以通過代碼更改的,這樣能更匹配 App的界面風格,下面是改變iPhone鍵盤顏⾊色的代碼。

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

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

for(UIView *w in ws)

{

NSArray *vs = [w subviews]; 

for(UIView *v in vs)

{

 

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

{

v.backgroundColor = [UIColor blueColor];

} }

} }

55 / 255 55 / 255

_textField.keyboardAppearance = UIKeyboardAppearanceAlert;//有這個設置屬性 才起作用

 

40、iPhone上實現Default.png動畫 添加一張和Default.png⼀一樣的圖片,對這個圖片進行動畫,從而實現Default動畫的漸變消 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:nil context: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、將EGO主題色添加到xcode中 打開終端,執行以下命令

Shell代碼

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

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

EGO.xccolortheme

然後,重啟Xcode,選擇Preferences > Fonts & Colors,最後從Color Theme 中選擇EGO即可。

 

42、將圖片保存到圖片庫中

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

UITouch *touch = [touches anyObject]; 

if ([touch tapCount]== 1)

{

UIImageWriteToSavedPhotosAlbum([ANImageView image], nil, nil, nil);

UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"存儲照⽚片 message:@"您已將照⽚存於圖片庫中,打開照片程序即可查" delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil];

 

[alert show];

[alert release];

}

 

43、讀取plist文件

//取得文件路徑

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

名" ofType:@"plist"];

//讀取到一個字典

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

//讀取到一個數組

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

 

44、使用#pragma mark 加上這樣的標識後,在導航條上會顯示源文件上方法列表,這樣就可對功能相關的方法進行分隔,方便查看瞭。

設置UITabBarController默認的啟動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;

[store setInteger:selectedIndex forKey:@"selectedIndex"];

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

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

NSLog(@"⽤用戶已經設置的selectedIndex的值是:%d", index);

else { 

NSLog(@"請設置默認的值");

}

 

46、更改Xcode的缺省公司名 在終端中執行以下命令:

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

 

47、設置uiView,成圓角矩形 畫個圓角的矩形沒啥難的,有兩種方法:

1 。直接修改view的樣式,系統提供好的瞭:

view.layer.cornerRadius = 6;

view.layer.masksToBounds = YES; 用layer做就可以瞭,十分簡單。這個需要倒庫 QuartzCore.framework;

2. 在view 裡面畫圓角矩形 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);

用畫筆的方法,在drawRect裡面做。

 

48、畫圖時圖片倒轉解決方法

CGContextRef context = UIGraphicsGetCurrentContext(); CGContextSaveGState(context);

CGContextTranslateCTM(context, 0, self.bounds.size.height); CGContextScaleCTM(context, 1, -1);

drawImage = [UIImage imageNamed:@"12.jpg"];

CGImageRef image = CGImageRetain(drawImage.CGImage);

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

 

49、Nsstring 自適應文本寬高度

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

constrainedToSize:CGSizeMake(190, 200)];

float feelHeight = feelSize.height;

 

50、用HTTP協議,獲取www.baidu.com網站的HTML數據:

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

 

51、viewDidLoad中設置按鈕圖案

UIButton *button = [UIButton buttonWithType: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、鍵盤上的return鍵改成Done: textField.returnKeyType = UIReturnKeyDone;

 

53、textfield設置成為密碼框: [textField_pwd setSecureTextEntry:YES];

 

54、收回鍵盤: [textField resignFirstResponder]; 或者 [textfield addTarget:self action:@selector(textFieldDone:) forControlEvents:UIControlEventEditin gDidEndOnExit];

55、振動:

#import<AudioToolbox/AudioToolbox.h> //需加頭文件

方法一: AudioServicesPlayAlertSound(kSystemSoundID_Vibrate);

方法二: AudioServicesPlaySystemSound(kSystemSoundID_Vibrate); 當設備不支持方法一函數時,起蜂鳴作用, 而方法二支持所有設備

 

56、用Cocoa刪除文件:

NSFileManager *defaultManager = [NSFileManager defaultManager]; 

[defaultManager removeFileAtPath: tildeFilename  handler: nil];

 

57、UIView透明漸變與移動效果:

//動畫配制開始

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

//圖片上升動畫

CGRect rect = imgView.frame ;

rect.origin.y = 30;

imgView.frame = rect;

//半透明度漸變動畫

imgView.alpha = 0;

//提交動畫

[UIView commitAnimations];

 

58、在UIView的drawRect方法內,用Quartz2D API繪制一個像素寬的水平直線: 

-(void)drawRect:(CGRect)rect{

//獲取圖形上下文

CGContextRef context = UIGraphicsGetCurrentContext(); //設置圖形上下文的路徑繪制顏色 CGContextSetStrokeColorWithColor(context, [UIColor

whiteColor].CGColor); //取消防鋸齒

CGContextSetAllowsAntialiasing(context, NO); //添加線

CGContextMoveToPoint(context, 50, 50); 

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

CGContextDrawPath(context, kCGPathStroke); }

 

59、用UIWebView加載: www.baidu.com

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

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

[self.view addSubview:web]; 

[web release];

 

60、利用UIImageView實現動畫:

– (void)viewDidLoad {

[super viewDidLoad];

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

[self.view addSubview:fishAni];

 [fishAni release];

//設置動畫幀

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 ];

//設置動畫總時間 fishAni.animationDuration=1.0;

//設置重復次數,0表示不重復 fishAni.animationRepeatCount=0;

//開始動畫

[fishAni startAnimating]; }

 

61、用NSTimer做一個定時器,每隔1秒執行一次 pressedDone; 

-(IBAction)clickBtn:(id)sender{

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

[timer fire];

 }

 

62、利用蘋果機裡的相機進行錄像:

-(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:@"錄像" forState:UIControlStateNormal];

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

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

}

63、App中調用 iPhone的home + 電源鍵截屏功能 

// 前置聲明是消除警告

CGImageRef UIGetScreenImage();

CGImageRef img = UIGetScreenImage();

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

 

64、切割圖片的方法

//切割圖片

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

//設置需要截取的⼤大⼩小

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

//轉換

CGImageRef imageRef = image.CGImage;

//截取函數

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:nil withEvent:nil]; }

CGPathRelease(path);

return self; 

}

 

66、用戶按home鍵推送通知

UIApplication *app = [UIApplication sharedApplication]; 

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

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

NSLog(@"pressHome…"); 

}

 

67、在UIImageView中旋轉圖像:

float rotateAngle = M_PI; //M_PI為一角度

CGAffineTransform transform =CGAffineTransformMakeRotation(rotateA ngle);

imageView.transform = transform;

 

68、隱藏狀態欄:

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

方法二, 在應用程序的Info.plist 文件中將 UIStatusBarHidden 設置為YES; 

 

69、構建多個可拖動視圖:

@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庫

加入dylib庫時,必須在info中加入頭文件路徑。/usr/include/庫名(不要後綴)

 

71、iPhone iPad 中App名字如何支持多語言和顯示自定義名字

建立InfoPlist.strings,本地化此文件,然後在文件內添加: CFBundleDisplayName = "xxxxxxxxxxx"; //

這樣應⽤用程序就能顯示成設置的名字“xxxxxxxxxxx”. 

 

 

72、在數字鍵盤上添加button:

//定義一個消息中心

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

//addObserver:註冊一個觀察員 name:消息名稱

– (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];

//返回應用程序window

UIView* keyboard;

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

//遍歷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應用圖標上的弧形高光 有時候我們的應用程序不需要在圖標上加上默認的高光,可以在你的應用的 Info.plist中加入:

Icon already includes gloss effects YES

 

74、實現修改navigation的back按鈕 

self.navigationItem.backBarButtonItem =

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

 

75、給圖片加上陰影

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

//添加邊框

CALayer*layer = [pageContenterImageView layer];

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

layer.borderWidth=0.0f;

//添加四個邊陰影

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

pageContenterImageView.layer.shadowOffset=CGSizeMake(0,0); pageContenterImageView.layer.shadowOpacity=0.5; pageContenterImageView.layer.shadowRadius=5.0; 陰影渲染會嚴重消耗內存 ,導致程序咔嘰.

/*陰影效果*/

//添加邊框

CALayer*layer = [self.pageContenter layer];

layer.borderColor= [[UIColorwhiteColor]CGColor];

layer.borderWidth=0.0f;

//添加四個邊陰影

self.pageContenter.layer.shadowColor= [UIColorblackColor].CGColor;//陰影顏色

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

⼆二、給視圖加上陰影

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

content.backgroundColor=[UIColor orangeColor];

//content.layer.shadowOffset=10;

content.layer.shadowOffset = CGSizeMake(5, 3); content.layer.shadowOpacity = 0.6; content.layer.shadowColor = [UIColor blackColor].CGColor;

[self.window addSubview:content]; 

 

76、UIView有一個屬性,clipsTobounds 默認情況下是NO, 如果,我們想要view2把超出的那部份隱藏起來的話,就得改變它的父視圖也 就view1的clipsTobounds屬性值。

view1.clipsTobounds = YES;

使用objective-c 建立UUID UUID是128位的值,它可以保證唯一性。通常,它是由機器本身網卡的MAC地

址和當前系統時間來生成的。 UUID是由中劃線連接而成的字符串。例如:0A326293-BCDD-4788-8F2D-

C4D8E53C108B

在聲明文件中聲明一個方法:

#import <UIKit/UIKit.h>

@interface UUIDViewController : UIViewController { }

– (NSString *) createUUID;

@end

對應的實現文件中實現該方法:

– (NSString *) createUUID {

CFUUIDRef uuidObject = CFUUIDCreate(kCFAllocatorDefault);

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

CFRelease(uuidObject);

return uuidStr; }

 

77、iPhone iPad中橫屏顯示代碼 

1、強制橫屏

[application setStatusBarOrientation:UIInterfaceOrientationLandscapeRight animated:NO];

2、在infolist⾥裡⾯面加瞭Supported interface orientations這⼀一項,增加之後添加四個item就是 ipad的四個⽅方向

item0 UIInterfaceOrientationLandscapeLeft

item1 UIInterfaceOrientationLandscapeRight 這表明隻⽀支持橫屏顯⽰示 經常讓人混淆迷惑的問題 – 數組和其他集合類

 

78、當一個對象被添加到一個array, dictionary, 或者 set等這樣的集合類型中的時候,集合會retain它。 對應 的,當集合類被release的時候,它會發送對應的release消息給包含在其中的對象。 因此,如果你想建立一 個包含一堆number的數組,你可以像下面示例中的幾個方法來做

NSMutableArray *array; int i;

// …

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

NSNumber *n = [NSNumber numberWithInt: i];

[array addObject: n]; }

在這種情況下, 我們不需要retain這些number,因為array將替我們這麼做。 NSMutableArray *array;

int i;

// …

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

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

 [array addObject: n];

[n release];

}

在這個例子中,因為你使用瞭-alloc去建立瞭一個number,所以你必須顯式的-release它,以保證retain count的平衡。因為將number加入數組的時候,已經retain它瞭,所以數組中的number變量不會被release

 

79、UIView動畫停止調用方法遇到的問題

在實現UIView的動畫的時候,並且使⽤用UIView來重復調⽤用它結束的回調時候要 註意以下⽅方法中的finished參數

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

{

if([finishied boolValue] == YES)

//一定要判斷這句話,要不在程序中當多個View刷新的時候,就可能出現動畫異常的現象 {

//執行想要的動作 }

}

 

80、判斷在UIViewController中,viewWillDisappear的時候是push還是 pop出來

– (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、連接字符串小技巧

NSString *string1 = @"abc / cde";

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

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

NSLog( @"string1 is %@" , string1 ); 

NSLog( @"string2 is %@" , string2 ); NSLog( @"string3 is %@" , string3 ); 

打印結果如下:

string1 is abc cde string2 is abccde

 

82、隨文字大小label自適應

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.window addSubview:label];

NSString *text = @"this is ok";

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

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

CGRect rect= label.frame; rect.size = size;

[label setFrame: rect]; [label setText: text];

 

83、UILabel字體加粗

//加粗

lb.font = [UIFont fontWithName:@"Helvetica-Bold" size:20]; //加粗並且傾斜

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

 

84、為IOS應用組件添加圓角的方法 具體的實現是使用QuartzCore庫,下面我具體的描述一下實現過程:

• 首先創建一個項目,名字叫:ipad_webwiew

• 利⽤用Interface Builder添加⼀一個UIWebView,然後和相應的代碼相關聯 • 添加QuartzCore.framework

代碼實現: 頭⽂文件:

#import <UIKit/UIKit.h>

#import <QuartzCore/QuartzCore.h>

@interface ipad_webwiewViewController : UIViewController {

IBOutlet UIWebView *myWebView; UIView *myView;

}

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

代碼實現:

– (void)viewDidLoad {

[super viewDidLoad]; //給圖層添加背景圖⽚片: //myView.layer.contents = (id)[UIImage

imageNamed:@"view_BG.png"].CGImage; //將圖層的邊框設置為圓腳

myWebView.layer.cornerRadius = 8; myWebView.layer.masksToBounds = YES; //給圖層添加⼀一個有⾊色邊框

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

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

 

85、實現UIToolBar的自動消失 

-(void)showBar

{

! [UIView beginAnimations:nil context: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: nil afterDelay: 3.0];

}

– (void)delayHideBars { [self showBar];

}

 

86、自定義UINavigationItem.rightBarButtonItem

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

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

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

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

[segmentedControl setMomentary:YES];

[segmentedControl addTarget:self action:@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];

想要從第五層直接返回到第二層或第三層,用索引的形式

[self.navigationController popToViewController: [self.navigationController.viewControllers objectAtIndex: ([self.navigationController.viewControllers count] – 2)] animated:YES];

 

87、鍵盤監聽事件

#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:nil context: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強制橫屏的方法:

在appDelegate裡調用

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

        [[UIApplication sharedApplication]

setStatusBarOrientation:

UIInterfaceOrientationLandscapeRight animated:NO];

    }

 

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