加载到NSArray/NSMutableArray里的对象,不需要负责release
The objects added to NSArray/NSMutableArray need not to be released.
copy是创建,retain是引用
the copy operation is create a new one,but the retain operation is just a reference.
you触摸的不是UIEvent,而是NSSet的UIView
what you touch on screen is not UIEvent but UIView
屏幕上看到的,都是UIVew
Everything you see on Screen is UIView.
UIApplicationDelegate负责应用程序的生命周期,而UIViewController负责View的生命周期
UIApplicationDelegate is responsible for the application life cycle,but UIViewController for the UIView.
如果对性能要求高,慎用Interface Build
if application’s performance is important,be discreet for the interface build.
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]; orNSDateFormatter *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 *)navigationBarshouldPopItem:(UINavigationItem *)item{ //在此处添加点击back按钮之后的操作代码 return NO;} //uilable自动换行CGSize titleBrandSizeForHeight = [titleBrand.text sizeWithFont:titleBrand.font];CGSize titleBrandSizeForLines = [titleBrand.text sizeWithFont:titleBrand.font constrainedToSize:CGSizeMake(infoWidth, MAXFLOAT) lineBreakMode:UILineBreakModeWordWrap];titleBrand.numberOfLines = ceil(titleBrandSizeForLines.height/titleBrandSizeForHeight.height);if (titleBrand.numberOfLines <= 1) { titleBrand.frame = CGRectMake(5, titleBrand.frame.size.height , infoWidth, titleBrandSizeForHeight.height);}else { titleBrand.frame = CGRectMake(5, titleBrand.frame.size.height , infoWidth, titleBrand.numberOfLines*titleBrandSizeForHeight.height);}//UIButton 点击事件 //创建UIButton UIButton *sampleButton =[UIButton buttonWithType:UIButtonTypeRoundedRect]; [sampleButton setFrame:CGRectMake(240,25,60,30)]; [sampleButton setTitle:@"聊天" forState:UIControlStateNormal]; [sampleButton.titleLabel setFont:[UIFont boldSystemFontOfSize:14]]; [sampleButton addTarget:self action:@selector(onBtnClick:) forControlEvents:UIControlEventTouchUpInside];//onBtnClick为方法名称-(void) onBtnClick:(id)sender{ NSLog(@"按钮点击事件");}//UIAlertView 输出 UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"提示" message:@"提示信息" delegate:self cancelButtonTitle:@"取消" otherButtonTitles:nil]; //此括号中的属性不可少 cancelButtonTitle属于alert所有按钮中的一个 [alert addButtonWithTitle:@"按钮2"]; [alert addButtonWithTitle:@"按钮3"]; [alert show];//弹出窗口按钮的点击事件-(void)alertView:(UIAlertView *)alertView didDismissWithButtonIndex:(NSInteger)buttonIndex{ switch (buttonIndex) { case 0: NSLog(@"点击取消"); break; case 1: NSLog(@"点击创建"); break; case 2: NSLog(@"点击搜索"); break; } [alertView release];}