iphone开发常用编码

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;

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