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;
}