1. stringWithFormat 用法：

[NSString stringWithFormat:@"Hight: %d°%@   Low: %d°%@", [Temp],@"C",[lTemp],@"C"];

NSString to NSData:

NSString* str= @"kilonet";

NSData* data=[str dataUsingEncoding:NSUTF8StringEncoding];

2. NSDate 用法：

NSDate  *today;

NSDate *tomorrow;

today = [NSDate date];

tomorrow = [NSDate dateWithTimeInterval:(i*24*60*60) sinceDate:today]; //可能有更好的

Date format用法：

-(NSString *) getDay:(NSDate *) d {

NSString *s ;

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

[format setDateFormat:@"YYYY/MM/dd hh:mm:ss"];

s = [format stringFromDate:d];

[format release];

return s;

}

各地时区获取：

代码

NSDate *nowDate = [NSDate new];

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

[formatter    setDateFormat:@"yyyy/MM/dd HH:mm:ss"];

//    根据时区名字获取当前时间，如果该时区不存在，默认获取系统当前时区的时间

//    NSTimeZone* timeZone = [NSTimeZone timeZoneWithName:@"Europe/Andorra"];

//    [formatter setTimeZone:timeZone];

//获取所有的时区名字

NSArray *array = [NSTimeZone knownTimeZoneNames];

//    NSLog(@"array:%@",array);

//for循环

//    for(int i=0;i<[array count];i++)

//    {

//        NSTimeZone* timeZone = [NSTimeZone timeZoneWithName:[array objectAtIndex:i]];

//        [formatter setTimeZone:timeZone];

//        NSString *locationTime = [formatter stringFromDate:nowDate];

//        NSLog(@"时区名字:%@   : 时区当前时间: %@",[array objectAtIndex:i],locationTime);

//        //NSLog(@"timezone name is:%@",[array objectAtIndex:i]);

//    }

//快速枚举法

for(NSString *timeZoneName in array){

[formatter setTimeZone:[NSTimeZone timeZoneWithName:timeZoneName]];

NSLog(@"%@,%@",timeZoneName,[formatter stringFromDate:nowDate]);

}

[formatter release];

[nowDate release];

获取毫秒时间：

代码

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

[dateFormatter setDateStyle:NSDateFormatterMediumStyle];

[dateFormatter setTimeStyle:NSDateFormatterShortStyle];

//[dateFormatter setDateFormat:@"hh:mm:ss"]

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

NSLog(@"Date%@", [dateFormatter stringFromDate:[NSDate date]]);

[dateFormatter release];

3. NSCalendar用法：

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

NSCalendar *calendar = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];

unsigned units = NSYearCalendarUnit | NSMonthCalendarUnit |  NSDayCalendarUnit | NSWeekdayCalendarUnit;

NSDateComponents *components = [calendar components:units fromDate:d];

[calendar release];

switch ([components weekday]) {

case 2:

return @"Monday";

break;

case 3:

return @"Tuesday";

break;

case 4:

return @"Wednesday";

break;

case 5:

return @"Thursday";

break;

case 6:

return  @"Friday";

break;

case 7:

return  @"Saturday";

break;

case 1:

return @"Sunday";

break;

default:

return @"No Week";

break;

}

// 用components，我们可以读取其他更多的数据。

}

4. 用Get方式读取网络数据：

// 将网络数读取为字符串

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

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

}

//读取网络图片

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

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

}

5. 多线程NSThread用法 ：

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

-(void) scheduleTask {

//create a pool

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

//release the pool;

[pool release];

}

//如果有参数，则这么使用：

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

-(void) scheduleTask:(NSDate *) mdate {

//create a pool

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

//release the pool;

[pool release];

}

//注意selector里有冒号。

//在线程里运行主线程里的方法

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

6. 定时器NSTimer用法:

代码

// 一个可以自动关闭的Alert窗口

UIAlertView *alert = [[UIAlertView alloc] initWithTitle:nil

message:[@"一个可以自动关闭的Alert窗口"

delegate:nil

cancelButtonTitle:nil //NSLocalizedString(@"OK", @"OK")   //取消任何按钮

otherButtonTitles:nil];

//[alert setBounds:CGRectMake(alert.bounds.origin.x, alert.bounds.origin.y, alert.bounds.size.width, alert.bounds.size.height+30.0)];

[alert show];

UIActivityIndicatorView *indicator = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleWhiteLarge];

// Adjust the indicator so it is up a few pixels from the bottom of the alert

indicator.center = CGPointMake(alert.bounds.size.width/2,  alert.bounds.size.height-40.0);

[indicator startAnimating];

[alert insertSubview:indicator atIndex:0];

[indicator release];

[NSTimer scheduledTimerWithTimeInterval:3.0f

target:self

selector:@selector(dismissAlert:)

userInfo:[NSDictionary dictionaryWithObjectsAndKeys:alert, @"alert", @"testing ", @"key" ,nil]  //如果不用传递参数，那么可以将此项设置为nil.

repeats:NO];

NSLog(@"release alert");

[alert release];

-(void) dismissAlert:(NSTimer *)timer{

NSLog(@"release timer");

NSLog([[timer userInfo]  objectForKey:@"key"]);

UIAlertView *alert = [[timer userInfo]  objectForKey:@"alert"];

[alert dismissWithClickedButtonIndex:0 animated:YES];

}

定时器停止使用：

[timer invalidate];

timer = nil;

7. 用户缺省值NSUserDefaults读取：

//得到用户缺省值

NSUserDefaults *defs = [NSUserDefaults standardUserDefaults];

//在缺省值中找到AppleLanguages, 返回值是一个数组

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

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

//在得到的数组中的第一个项就是用户的首选语言了

NSLog(@"首选语言 is %@",[languages objectAtIndex:0]);

//get the language & country code

NSLocale *currentLocale = [NSLocale currentLocale];

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

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

8. View之间切换的动态效果设置：

SettingsController *settings = [[SettingsController alloc]initWithNibName:@"SettingsView" bundle:nil];

settings.modalTransitionStyle = UIModalTransitionStyleFlipHorizontal;  //水平翻转

[self presentModalViewController:settings animated:YES];

[settings release];

9.NSScrollView 滑动用法：

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

NSLog(@"正在滑动中...");

}

//用户直接滑动NSScrollView，可以看到滑动条

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

}

// 通过其他控件触发NSScrollView滑动，看不到滑动条

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

}

10. 读取全局的Delegate：

KiloNetAppDelegate *appdelegate = (KiloNetAppDelegate *)[[UIApplication sharedApplication] delegate];

11.键盘处理系列

//set the UIKeyboard to switch to a different text field when you press return

//switch textField to the name of your textfield

[textField becomeFirstResponder];

12. 半透明层的实现：

半透明层

+(void)showWaiting:(UIView *)parent {

int width = 32, height = 32;

CGRect frame = [parent frame]; //[[UIScreen mainScreen] applicationFrame];

int x = frame.size.width;

int y = frame.size.height;

frame = CGRectMake((x - width) / 2, (y - height) / 2, width, height);

UIActivityIndicatorView* progressInd = [[UIActivityIndicatorView alloc] initWithFrame:frame];

[progressInd startAnimating];

progressInd.activityIndicatorViewStyle = UIActivityIndicatorViewStyleWhiteLarge;

//    frame = CGRectMake((x - 140)/2, (y - height) / 2 + height, 140, 30);

//    UILabel *waitingLable = [[UILabel alloc] initWithFrame:frame];

//    waitingLable.text = @"Proccesing...";

//    waitingLable.textColor = [UIColor whiteColor];

//    waitingLable.font = [UIFont systemFontOfSize:15];

//    waitingLable.backgroundColor = [UIColor clearColor];

frame = [parent frame];

UIView *theView = [[UIView alloc] initWithFrame:frame];

theView.backgroundColor = [UIColor blackColor];

theView.alpha = 0.8;

[theView addSubview:progressInd];

//  [theView addSubview:waitingLable];

[progressInd release];

//    [waitingLable release];

[theView setTag:9999];

[parent addSubview:theView];

[theView release];

}

+(void)hideWaiting:(UIView *)parent {

[[parent viewWithTag:9999] removeFromSuperview];

}

13. 设置View的圆角：

// 首先应用  #import <QuartzCore/QuartzCore.h>

view.layer.cornerRadius = 10;

view.layer.masksToBounds = YES;

14. UIWebView显示本地图片(目前有点问题，无法正确显示图片):

代码

NSString *imagePath = [[NSBundle mainBundle] resourcePath];

imagePath = [imagePath stringByReplacingOccurrencesOfString:@"/" withString:@"//"];

imagePath = [imagePath stringByReplacingOccurrencesOfString:@" " withString:@"%20"];

NSLog(@"fileurl=%@",[NSString stringWithFormat:@"file:/%@//",imagePath]);

//[self loadData:[html dataUsingEncoding:NSUTF8StringEncoding] MIMEType:@"text/html" textEncodingName:@"UTF-8" baseURL:[NSURL fileURLWithPath:[NSString stringWithFormat:@"file:/%@//",imagePath]] ];

[self loadHTMLString:html baseURL:[NSURL fileURLWithPath:[NSString stringWithFormat:@"file:/%@//",imagePath]   ]];

NSString *path = [[NSBundle mainBundle] bundlePath];

NSURL *baseURL = [NSURL fileURLWithPath:path];

[UIWebView loadHTMLString:html baseURL:baseURL];

//这段代码可以正确显示图片。

1. 随机数：

srandom(time(NULL)); //随机数种子

id d = random(); // 随机数

2. 视频播放：

MPMoviePlayerController *moviePlayer;

moviePlayer = [[MPMoviePlayerController alloc]

initWithContentURL:[NSURL fileURLWithPath:[[NSBundle mainBundle] pathForResource:@"Movie" ofType:@"m4v"]]];

//初始化视频播放器对象，并传入被播放文件的地址

moviePlayer.movieControlMode = MPMovieControlModeDefault;

[moviePlayer play];

//此处有内存溢出

3.  启动界面显示：

iPhone软件启动后的第一屏图片是非常重要的往往就是loading载入中的意思。设置它说来也简单，但是却无比重要

只需要在resource里面将你希望设置的图片更名为Default.png，这个图片就可以成为iPhone载入的缺省图片

4. 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 *tempPath = NSTemporaryDirectory();

//得到目录上的文件地址：

NSString *文件地址 = [目录地址 stringByAppendingPathComponent:@"文件名.扩展名"];

5. 状态栏显示Indicator：

[UIApplication sharedApplication].networkActivityIndicatorVisible = YES;

6.app Icon显示数字：

- (void)applicationDidEnterBackground:(UIApplication *)application{

[[UIApplication sharedApplication] setApplicationIconBadgeNumber:5];

}

7.sqlite保存地址：

代码

NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);

NSString *thePath = [paths objectAtIndex:0];

NSString *filePath = [thePath stringByAppendingPathComponent:@"kilonet1.sqlite"];

NSString *dbPath = [[[NSBundle mainBundle] resourcePath]

stringByAppendingPathComponent:@"kilonet2.sqlite"];

8.Application退出：exit(0);

9. AlertView，ActionSheet的cancelButton点击事件：

代码

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

NSLog(@"cancel actionSheet........");

//当用户按下cancel按钮

if( buttonIndex == [actionSheet cancelButtonIndex]) {

exit(0);

}

//    //当用户按下destructive按钮

//    if( buttonIndex == [actionSheet destructiveButtonIndex]) {

//        // DoSomething here.

//    }

}

- (void)alertView:(UIAlertView *)alertView willDismissWithButtonIndex:(NSInteger)buttonIndex {

NSLog(@"cancel alertView........");

if (buttonIndex == [alertView cancelButtonIndex]) {

exit(0);

}

}

10.给Window设置全局的背景图片：

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

11. UITextField文本框显示及对键盘的控制:

代码

#pragma mark -

#pragma mark UITextFieldDelegate

//控制键盘跳转

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

if (textField == _txtAccount) {

if ([_txtAccount.text length]==0) {

return NO;

}

[_txtPassword becomeFirstResponder];

} else if (textField == _txtPassword) {

[_txtPassword resignFirstResponder];

}

return YES;

}

//输入框背景更换

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

[textField setBackground:[UIImage imageNamed:@"ctext_field_02.png"]];

return YES;

}

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

[textField setBackground:[UIImage imageNamed:@"ctext_field_01.png"]];

}

12.UITextField文本框前面空白宽度设置以及后面组合按钮设置：

代码

//给文本输入框后面加入空白

_txtAccount.rightView = _btnDropDown;

_txtAccount.rightViewMode =  UITextFieldViewModeAlways;

//给文本输入框前面加入空白

CGRect frame = [_txtAccount frame];

frame.size.width = 5;

UIView *leftview = [[UIView alloc] initWithFrame:frame];

_txtAccount.leftViewMode = UITextFieldViewModeAlways;

_txtAccount.leftView = leftview;

13. UIScrollView 设置滑动不超出本身范围：

[fcScrollView setBounces:NO];

14. 遍历View里面所有的Subview：

代码

NSLog(@"subviews count=%d",[self.view.subviews count]);

if ([self.view.subviews count] > 0) {

for (UIView *curView in self.view.subviews) {

NSLog(@"view.subviews=%@", [NSString stringWithUTF8String:object_getClassName(curView)]);

}

}

14. 在drawRect里画文字：

UIFont * f = [UIFont systemFontOfSize:20];

[[UIColor darkGrayColor] set];

NSString * text = @"hi \nKiloNet";

[text drawAtPoint:CGPointMake(center.x,center.y) withFont:f];

15. NSArray查找是否存在对象时用indexOfObject,如果不存在则返回为NSNotFound.

16. NString与NSArray之间相互转换：

array = [string componentsSeparatedByString:@","];

string = [[array valueForKey:@"description"] componentsJoinedByString:@","];

17. TabController随意切换tab bar：

[self.tabBarController setSelectedIndex:tabIndex];

或者 self.tabBarController.selectedIndex = tabIndex;

或者实现下面的delegate来扑捉tab bar的事件：

代码

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

if ([viewController.tabBarItem.title isEqualToString: NSLocalizedString(@"Logout",nil)]) {

[self showLogout];

return NO;

}

return YES;

}

18. 自定义View之间切换动画：

代码

- (void) pushController: (UIViewController*) controller

withTransition: (UIViewAnimationTransition) transition

{

[UIView beginAnimations:nil context:NULL];

[self pushViewController:controller animated:NO];

[UIView setAnimationDuration:.5];

[UIView setAnimationBeginsFromCurrentState:YES];

[UIView setAnimationTransition:transition forView:self.view cache:YES];

[UIView commitAnimations];

}

或者：

代码

CATransition *transition = [CATransition animation];

transition.duration = kAnimationDuration;

transition.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];

transition.type = kCATransitionPush;

transition.subtype = kCATransitionFromTop;

transitioning = YES;

transition.delegate = self;

[self.navigationController.view.layer addAnimation:transition forKey:nil];

self.navigationController.navigationBarHidden = NO;

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

19. UIWebView加载时白色显示问题解决以及字体统一设置：

uiWebView.opaque = NO;

代码

20.计算字符串长度：

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

21. iTunesLink should be your applications link

NSString *iTunesLink = @"http://phobos.apple.com/WebObjects/MZStore.woa/wa/viewSoftware?id=xxxxxx&mt=8";

[[UIApplication sharedApplication] openURL:[NSURL URLWithString:iTunesLink]];

22.时间转换NSString & NSDate：

-(NSDate *)NSStringDateToNSDate:(NSString *)string {

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

[formatter setTimeZone:[NSTimeZone timeZoneWithAbbreviation:@"UTC"]];

[formatter setDateFormat:@"yyyy-MM-dd"];

NSDate *date = [formatter dateFromString:string];

[formatter release];

return date;

}

NSString *year = [myDate descriptionWithCalendarFormat:@"%Y" timeZone:nil locale:nil];

or

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

[formatter setDateFormat:@"yyyy"];

//Optionally for time zone converstions

[formatter setTimeZone:[NSTimeZone timeZoneWithName:@"..."]];

NSString *stringFromDate = [formatter stringFromDate:myNSDateInstance];

22。 模拟器的文件位置

其中#username#表示当前用户名:

/Users/#username#/Library/Application Support/iPhone Simulator/User/Applications/

23.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：

1

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

背景完全消除了，只剩下搜索框本身了。

24.  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

25. iphone-常用的对视图图层(layer)的操作

对图层的操作：

(1.给图层添加背景图片：

myView.layer.contents = (id)[UIImage imageNamed:@"view_BG.png"].CGImage;

(2.将图层的边框设置为圆脚

myWebView.layer.cornerRadius = 8;

myWebView.layer.masksToBounds = YES;

(3.给图层添加一个有色边框

myWebView.layer.borderWidth = 5;

myWebView.layer.borderColor = [[UIColor colorWithRed:0.52 green:0.09 blue:0.07 alpha:1] CGColor];

26. UIPopoverController 使用

-(void) onSetting:(id) sender {

SplitBaseController *detail = [[SettingServerController alloc] init];

CGRect frame = [(UIView *)sender frame];

frame.origin.y = 0;

UIPopoverController *popwin = [[UIPopoverController alloc] initWithContentViewController:detail];

[popwin setPopoverContentSize:CGSizeMake(400, 300) animated:YES];

popwin.delegate = self;

[popwin presentPopoverFromRect: frame inView:self.view permittedArrowDirections:UIPopoverArrowDirectionAny animated:YES];

[detail release];

}

27.在UINavigationBar中添加左箭头返回按钮

在iPhone里面最讨厌的控件之一就是 UINavigationBar了。这个控件样式修改不方便，连添加按钮也特别麻烦。下面的例子是如何手动添加带箭头的按钮：

UINavigationItem *item = [navBar.items objectAtIndex:0];

UINavigationItem *back = [[UINavigationItem alloc] initWithTitle:@"Back"];

NSArray *items = [[NSArray alloc] initWithObjects:back,item,nil];

[navBar setItems:items];

- (BOOL)navigationBar:(UINavigationBar *)navigationBar

shouldPopItem:(UINavigationItem *)item{

//在此处添加点击back按钮之后的操作代码

return NO;

}