1，獲取翻轉事件，並開啟翻轉：
只要在viewcontroller的類中加入
-(BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation{
//翻轉后要執行的代碼
return YES;
}
2，-(void)viewWillAppear:(BOOL)animated，- (void)viewDidLoad 的區別。
viewwillappear是每次視圖控制器的視圖出現前執行的代碼。而viewdidload是每次視圖控制器載入是執行的代碼。
比如說：當a視圖控制器的視圖第一次出現是兩個都要執行，但當a被push后有pop回來時，只有viewwillappear執行。
3，如何讓視圖始終跟着手指移動，並有反彈事件
xsum=photopositon.origin.x+photopositon.size.width/2-touchstart.x;
ysum=photopositon.origin.y+photopositon.size.height/2-touchstart.y;
currentview.center=CGPointMake(xsum+p.x, ysum+p.y);
if (pow(currentview.center.x-160,2.0)>pow(photopositon.size.width/2,2.0)||
pow(currentview.center.y-240,2.0)>pow(photopositon.size.height/2, 2.0))
{
[UIView beginAnimations:nil context:NULL];
[UIView setAnimationCurve:UIViewAnimationCurveEaseInOut];
[UIView setAnimationDuration:0.3];
currentview.center=CGPointMake(160, 240);
[UIView commitAnimations];
}
就是讓currentview的視圖中心始終與手指保持一定的方位。
4，控制導航條和toolbar
[self.navigationController ...］
[self.navigationController.toolbar ...］
比如說讓他們都消失：
[self.navigationController setToolbarItems:NULL animated:YES];
[self.navigationController.toolbar setBarStyle:UIBarStyleBlackTranslucent];
[self.navigationController setToolbarHidden:NO animated:YES];
5，自定義控件事件：
addTarget:self action:@selector(....) forControlEvents:....
比如獲取某個按鈕的觸摸事件；
[new addTarget:self action:@selector(onChooseItem:) forControlEvents:UIControlEventTouchUpInside]
則當按鈕按下時，- (void)onChooseItem:(id) sender 就會被調用。
sender傳的就是被按下按鈕的指針。
6.獲取文件的路徑，即獲取documents的路徑
//獲取文件路徑
NSArray *path=NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsPath=[path objectAtIndex:0];
NSLog(@"%@",documentsPath);
補充：
1. NSSearchPathForDirectoriesInDomains和NSHomeDirectory
iPhone和symbian 3rd一樣，會為每一個應用程序生成一個私有目錄，這個目錄位於/Users/sundfsun2009/Library/Application Support/iPhone Simulator/User/Applications下，並隨即生成一個數字字母串作為目錄名，在每一次應用程序啟動時，這個字母數字串都是不同於上一次。
通常使用Documents目錄進行數據持久化的保存，而這個Documents目錄可以通過 NSSearchPathForDirectoriesInDomains（NSDocumentDirectory，NSUserdomainMask，YES） 得到，代碼如下：
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
// NSString *path = [documentsDirectory stringByAppendingPathComponent:@"aa.plist"];
NSLog(@"path: %@",path);
打印結果如下：
path: /Users/apple/Library/Application Support/iPhone Simulator/4.3/Applications/550AF26D-174B-42E6-881B-B7499FAA32B7/Documents
而這個目錄還可以通過 NSHomeDirectory()來得到，代碼如下：
NSString *destPath = NSHomeDirectory();
NSLog(@"path: %@",destPath);
//destPath = [destPath stringByAppendingPathComponent: @"Documents"];
//NSString *xmlpath = [destPath stringByAppendingPathComponent: @"menu/menu.xml"];
打印結果如下：
path: /Users/apple/Library/Application Support/iPhone Simulator/4.2/Applications/6F4BC466-C5D6-440C-BAAC-BE20FA468C61
看看兩者打印出來的結果，我們可以看出這兩種方法的不同。
2. 瀏覽document下所有圖片資源
#define DOCUMENTS_FOLDER [NSHomeDirectory() stringByAppendingPathComponent:@"Documents"]
NSArray *fileList = [[[NSFileManager defaultManager] directoryContentsAtPath:DOCUMENTS_FOLDER]
pathsMatchingExtensions:[NSArray arrayWithObject:@"png"]] ;
3. 得到圖片中的某一部分：
UIImage *image = [UIImage imageNamed:filename];
CGImageRef imageRef = image.CGImage;
CGRect rect = CGRectMake(origin.x, origin.y ,size.width, size.height);
CGImageRef imageRefRect = CGImageCreateWithImageInRect(imageRef, rect);
UIImage *imageRect = [[UIImage alloc] initWithCGImage:imageRefRect];
7.在documents的路徑下創建文件。
首先要獲取documents的路徑，如上第6條。
其次就是下面的語句了：
NSString *writePath=[NSString stringWithFormat:@"%@/%@.txt",documentsPath,@"aaa"];
NSData *data = [@"" dataUsingEncoding:NSUTF8StringEncoding];//新文件的初始數據，設為空
[[NSFileManager defaultManager] createFileAtPath:writePath contents:data attributes:nil];//創建文件的命令在這里
這樣就可以在documents文件夾下創建一個aaa.txt的文件了。哈哈哈哈哈。
或者是用下面的語句，
NSString *writePath=[NSString stringWithFormat:@"%@/%@.txt",documentsDirectory,@"bbb"];
NSError *error;
[@"fasdfasdasddaa" writeToFile:writePath atomically:YES encoding:NSUTF8StringEncoding error:&error];
這樣就可以在documents文件夾下創建一個bbb.txt的文件了。並且，文件中的有"fasdfasdasddaa"字符。
總結起來就是，先給要存儲的東西取一個名字，然后，找到它的路徑。然后以這個名字創建。創建的時候可以添加內容。
當然，圖片也可以批量的生成，假如說讓你把一張圖片復制500遍，並且給他按照（1－500）重命名。
你可以用上面的方法，用一個循環批量的生成500張圖片。
UIImage *image = [UIImage imageNamed:@"240*360.png"];
NSData *data = UIImagePNGRepresentation(image);
NSString *documentPath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
NSMutableArray *muArray;
NSString *filePath = nil;
for (int j = 1; j<=500; j++) {
filePath = [[NSString alloc] initWithFormat:@"%@/%d.png",documentPath,j];
[data writeToFile:filePath atomically:YES];
NSString *newPath = [[NSString alloc] initWithFormat:@"%@",documentPath];
muArray = [[NSMutableArray alloc] initWithContentsOfFile:newPath];
[muArray addObject:filePath];
[filePath release];
｝
7.iphone開發中隨機數的產生。
// Get random number between 0 and 99
int x = arc4random() % 81;
// Get random number between 500 and 999
int y = ((arc4random()%501)+500);
NSLog(@"0－－99之間的隨機數%d",x);
NSLog(@"500－－999之間的隨機數%d",y);
8.好看的文字處理
以tableView中cell的textLabel為例子：
cell.backgroundColor = [UIColor scrollViewTexturedBackgroundColor];
//設置文字的字體
cell.textLabel.font = [UIFont fontWithName:@"American Typewriter" size:100.0f];
//設置文字的顏色
cell.textLabel.textColor = [UIColor orangeColor];
//設置文字的背景顏色
cell.textLabel.shadowColor = [UIColor whiteColor];
//設置文字的顯示位置
cell.textLabel.textAlignment = UITextAlignmentCenter;
9.新手學習webview
//Web view
//A basic UIWebView.
CGRect webFrame = CGRectMake(0.0, 0.0, 320.0, 460.0);
UIWebView *webView = [[UIWebView alloc] initWithFrame:webFrame];
[webView setBackgroundColor:[UIColor whiteColor]];
NSString *urlAddress = @"http://www.google.com";
NSURL *url = [NSURL URLWithString:urlAddress];
NSURLRequest *requestObj = [NSURLRequest requestWithURL:url];
[webView loadRequest:requestObj];
[self addSubview:webView];
[webView release]
10。———————-隱藏Status Bar—————————–
讀者可能知道一個簡易的方法,那就是在程序的viewDidLoad中加入
[[UIApplication sharedApplication] setStatusBarHidden:YES animated:NO];
11.更改AlertView背景
UIAlertView *theAlert = [[[UIAlertViewalloc] initWithTitle:@"Atention"
message: @"I'm a Chinese!"
delegate:nil
cancelButtonTitle:@"Cancel"
otherButtonTitles:@"Okay",nil] autorelease];
[theAlert show];
UIImage *theImage = [UIImage imageNamed:@"loveChina.png"];
theImage = [theImage stretchableImageWithLeftCapWidth:0topCapHeight:0];
CGSize theSize = [theAlert frame].size;
UIGraphicsBeginImageContext(theSize);
[theImage drawInRect:CGRectMake(5, 5, theSize.width-10, theSize.height-20)]; //這個地方的大小要自己調整，以適應alertview的背景顏色的大小。
theImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
theAlert.layer.contents = (id)[theImage CGImage];
12。iOS后台播放聲音
[session setActive:YES error:nil];
[session setCategory:AVAudioSessionCategoryPlayback error:nil];
13。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。
UITextInputTraits屬性
autocapitalizationType 設置鍵盤自動大小寫的屬性 UITextAutocapitalizationTypeNone
autocorrectionType property 設置是否有自動修改提示 UITextAutocorrectionTypeNo
enablesReturnKeyAutomatically Boolean值－設置在用戶沒有輸入是returnKey禁用，默認值NO
keyboardAppearance 設置鍵盤顯示方式 除了默認模式 還有一個UIKeyboardAppearanceAlert模式
keyboardType 設置鍵盤類型 UIKeyboardTypePhonePad 等
returnKeyType 設置renturnKey按鍵上的提示文字 UIReturnKeyGo UIReturnKeyNext
secureTextEntry BOOL值 －－ 設置是否是密碼保護模式輸入
如下：
設置登錄用的 輸入框 UITextField
用戶名輸入框：
m_TF_username = [[UITextField alloc] initWithFrame:my_frame];
m_TF_username.borderStyle = UITextBorderStyleNone;
m_TF_username.clearButtonMode = UITextFieldViewModeWhileEditing;
m_TF_username.delegate = self;
m_TF_username.returnKeyType = UIReturnKeyNext;
m_TF_username.autocapitalizationType = UITextAutocapitalizationTypeNone;
[m_TF_username becomeFirstResponder];
密碼輸入框：
m_TF_password = [[UITextField alloc] initWithFrame:my_frame];
m_TF_password.borderStyle = UITextBorderStyleNone;
m_TF_password.clearButtonMode = UITextFieldViewModeWhileEditing;
m_TF_password.delegate = self;
m_TF_password.returnKeyType = UIReturnKeyGo;
m_TF_password.secureTextEntry =YES;
鍵盤透明
textField.keyboardAppearance = UIKeyboardAppearanceAlert;
狀態欄的網絡活動風火輪是否旋轉
[UIApplication sharedApplication].networkActivityIndicatorVisible，默認值是NO。
截取屏幕圖片
//創建一個基於位圖的圖形上下文並指定大小為CGSizeMake(200,400)
UIGraphicsBeginImageContext(CGSizeMake(200,400));
//renderInContext 呈現接受者及其子范圍到指定的上下文
[self.view.layer renderInContext:UIGraphicsGetCurrentContext()];
//返回一個基於當前圖形上下文的圖片
UIImage *aImage = UIGraphicsGetImageFromCurrentImageContext();
//移除棧頂的基於當前位圖的圖形上下文
UIGraphicsEndImageContext();
//以png格式返回指定圖片的數據
imageData = UIImagePNGRepresentation(aImage);
更改cell選中的背景
UIView *myview = [[UIView alloc] init];
myview.frame = CGRectMake(0, 0, 320, 47);
myview.backgroundColor = [UIColor colorWithPatternImage:[UIImage imageNamed:@"0006.png"]];
cell.selectedBackgroundView = myview;
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:注冊一個觀察員 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];
}
}
正則表達式使用：
被用於正則表達式的字串必須是可變長的，不然會出問題
將一個空間放在視圖之上
[scrollView insertSubview:searchButton aboveSubview:scrollView];
從本地加載圖片
NSString *boundle = [[NSBundle mainBundle] resourcePath];
[web1 loadHTMLString:[NSString stringWithFormat:@"<img src='http://fei263.blog.163.com/blog/0001.png'/>"] baseURL:[NSURL fileURLWithPath:boundle]];
從網頁加載圖片並讓圖片在規定長寬中縮小
[cell.img loadHTMLString:[NSString stringWithFormat:@"<html><body><img src='http://fei263.blog.163.com/blog/%@' height='90px' width='90px'></body></html>",goodsInfo.GoodsImg] baseURL:nil];
將網頁加載到webview上通過javascript獲取里面的數據，如果只是發送了一個連接請求獲取到源碼以后可以用正則表達式進行獲取數據
NSString *javaScript1 = @"document.getElementsByName('.u').item(0).value";
NSString *javaScript2 = @"document.getElementsByName('.challenge').item(0).value";
NSString *strResult1 = [NSString stringWithString:[theWebView stringByEvaluatingJavaScriptFromString:javaScript1]];
NSString *strResult2 = [NSString stringWithString:[theWebView stringByEvaluatingJavaScriptFromString:javaScript2]];
用NSString怎么把UTF8轉換成unicode
utf8Str //
NSString *unicodeStr = [NSString stringWithCString:[utf8Str UTF8String] encoding:NSUnicodeStringEncoding];
View自己調用自己的方法:
[self performSelector:@selector(loginToNext) withObject:nil afterDelay:2];//黃色段為方法名,和延遲幾秒執行.
顯示圖像:
CGRect myImageRect = CGRectMake(0.0f, 0.0f, 320.0f, 109.0f);
UIImageView *myImage = [[UIImageView alloc] initWithFrame:myImageRect];
[myImage setImage:[UIImage imageNamed:@"myImage.png"]];
myImage.opaque = YES; //opaque是否透明
[self.view addSubview:myImage];
[myImage release];
WebView:
CGRect webFrame = CGRectMake(0.0, 0.0, 320.0, 460.0);
UIWebView *webView = [[UIWebView alloc] initWithFrame:webFrame];
[webView setBackgroundColor:[UIColor whiteColor]];
NSString *urlAddress = @"http://www.google.com";
NSURL *url = [NSURL URLWithString:urlAddress];
NSURLRequest *requestObj = [NSURLRequest requestWithURL:url];
[webView loadRequest:requestObj];
[self addSubview:webView];
[webView release];
顯示網絡活動狀態指示符
這是在iPhone左上部的狀態欄顯示的轉動的圖標指示有背景發生網絡的活動。
UIApplication* app = [UIApplication sharedApplication];
app.networkActivityIndicatorVisible = YES;
動畫:一個接一個地顯示一系列的圖象
NSArray *myImages = [NSArray arrayWithObjects: [UIImage imageNamed:@"myImage1.png"], [UIImage imageNamed:@"myImage2.png"], [UIImage imageNamed:@"myImage3.png"], [UIImage imageNamed:@"myImage4.gif"], nil];
UIImageView *myAnimatedView = [UIImageView alloc];
[myAnimatedView initWithFrame:[self bounds]];
myAnimatedView.animationImages = myImages; //animationImages屬性返回一個存放動畫圖片的數組
myAnimatedView.animationDuration = 0.25; //瀏覽整個圖片一次所用的時間
myAnimatedView.animationRepeatCount = 0; // 0 = loops forever 動畫重復次數
[myAnimatedView startAnimating];
[self addSubview:myAnimatedView];
[myAnimatedView release];
動畫:顯示了something在屏幕上移動。注：這種類型的動畫是“開始后不處理” -你不能獲取任何有關物體在動畫中的信息(如當前的位置) 。如果您需要此信息，您會手動使用定時器去調整動畫的X和Y坐標
這個需要導入QuartzCore.framework
CABasicAnimation *theAnimation;
theAnimation=[CABasicAnimation animationWithKeyPath:@"transform.translation.x"];
//Creates and returns an CAPropertyAnimation instance for the specified key path.
//parameter:the key path of the property to be animated
theAnimation.duration=1;
theAnimation.repeatCount=2;
theAnimation.autoreverses=YES;
theAnimation.fromValue=[NSNumber numberWithFloat:0];
theAnimation.toValue=[NSNumber numberWithFloat:-60];
[view.layer addAnimation:theAnimation forKey:@"animateLayer"];
Draggable items//拖動項目
Here's how to create a simple draggable image.//這是如何生成一個簡單的拖動圖象
1. Create a new class that inherits from UIImageView
@interface myDraggableImage : UIImageView { }
2. In the implementation for this new class, add the 2 methods:
- (void) touchesBegan:(NSSet*)touches withEvent:(UIEvent*)event
{
// Retrieve the touch point 檢索接觸點
CGPoint pt = [[touches anyObject] locationInView:self];
startLocation = pt;
[[self superview] bringSubviewToFront:self];
}
- (void) touchesMoved:(NSSet*)touches withEvent:(UIEvent*)event
{
// Move relative to the original touch point 相對以前的觸摸點進行移動
CGPoint pt = [[touches anyObject] locationInView:self];
CGRect frame = [self frame];
frame.origin.x += pt.x - startLocation.x;
frame.origin.y += pt.y - startLocation.y;
[self setFrame:frame];
}
3. Now instantiate the new class as you would any other new image and add it to your view
//實例這個新的類,放到你需要新的圖片放到你的視圖上
dragger = [[myDraggableImage alloc] initWithFrame:myDragRect];
[dragger setImage:[UIImage imageNamed:@"myImage.png"]];
[dragger setUserInteractionEnabled:YES];
線程:
1. Create the new thread:
[NSThread detachNewThreadSelector:@selector(myMethod) toTarget:self withObject:nil];
2. Create the method that is called by the new thread:
- (void)myMethod
{
NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
*** code that should be run in the new thread goes here ***
[pool release];
}
//What if you need to do something to the main thread from inside your new thread (for example, show a loading //symbol)? Use performSelectorOnMainThread.
[self performSelectorOnMainThread:@selector(myMethod) withObject:nil waitUntilDone:false];
Plist files
Application-specific plist files can be stored in the Resources folder of the app bundle. When the app first launches, it should check if there is an existing plist in the user's Documents folder, and if not it should copy the plist from the app bundle.
// Look in Documents for an existing plist file
NSArray *paths = NSSearchPathForDirectoriesInDomains( NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
myPlistPath = [documentsDirectory stringByAppendingPathComponent:
[NSString stringWithFormat: @"%@.plist", plistName] ];
[myPlistPath retain];
// If it's not there, copy it from the bundle
NSFileManager *fileManger = [NSFileManager defaultManager];
if ( ![fileManger fileExistsAtPath:myPlistPath] )
{
NSString *pathToSettingsInBundle = [[NSBundle mainBundle] pathForResource:plistName ofType:@"plist"];
}
//Now read the plist file from Documents
NSArray *paths = NSSearchPathForDirectoriesInDomains( NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectoryPath = [paths objectAtIndex:0];
NSString *path = [documentsDirectoryPath stringByAppendingPathComponent:@"myApp.plist"];
NSMutableDictionary *plist = [NSDictionary dictionaryWithContentsOfFile: path];
//Now read and set key/values
myKey = (int)[[plist valueForKey:@"myKey"] intValue];
myKey2 = (bool)[[plist valueForKey:@"myKey2"] boolValue];
[plist setValue:myKey forKey:@"myKey"];
[plist writeToFile:path atomically:YES];
Alerts
Show a simple alert with OK button.
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:nil message:
@"An Alert!" delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil];
[alert show];
[alert release];
Info button
Increase the touchable area on the Info button, so it's easier to press.
CGRect newInfoButtonRect = CGRectMake(infoButton.frame.origin.x-25, infoButton.frame.origin.y-25, infoButton.frame.size.width+50, infoButton.frame.size.height+50);
[infoButton setFrame:newInfoButtonRect];
Detecting Subviews
You can loop through subviews of an existing view. This works especially well if you use the "tag" property on your views.
for (UIImageView *anImage in [self.view subviews])
{
if (anImage.tag == 1)
{ // do something }
}
16.
//UILabel 和字體大小的匹配，可以用到制作電子書的時候。
//UILabel 和字體大小的匹配，可以用到制作電子書的時候。
NSString *str = @"UILabel 和字體大小的匹配.親愛的,在一起的日子很平淡，似乎波瀾不驚，只是，這種平凡的日子是最浪漫的，對嗎？遇到你之前，世界像一片荒草原；遇到你之后，世界像一個游樂園。過去的許多歲月，對我來說像一縷輕煙，未來的無限生涯，因你而幸福無邊。愛一個人是在夜里等待另一個人的呼吸,雖然隔着千里萬里,但我知道你在手機的那一端,於是我便會夜夜等待.守株待兔是人間最大的幸福,因為我有目標，你就是我要逮那只兔子,是我一生要好好照顧保護那個人.沒有你的時候，你就是我的世界；和你在一起時，世界就是你的。親愛的，情人節快樂。";
UIFont *font = [UIFont fontWithName:@"Arial" size:36.0f];
CGSize size = CGSizeMake(320, 2000);
UILabel *label = [[UILabel alloc] initWithFrame:CGRectZero];//先設為“0”的大小狀態
label.numberOfLines = 0;//當設為0的時候，label顯示多行。
CGSize labelSize = [str sizeWithFont:font constrainedToSize:size lineBreakMode:UILineBreakModeWordWrap];//得到size的寬和高
NSLog(@"%f",labelSize.height);
label.frame = CGRectMake(0, 0, labelSize.width, labelSize.height);
label.text = str;
label.font = font;
label.textColor = [UIColor blueColor];
[self.view addSubview:label];
[label release];
17.選中某一行的時候，該行顏色變化
[tableView deselectRowAtIndexPath:indexPath animated:NO];//選擇當前行，使得改行顏色變化，選中后的反顯顏色即刻消失。
18.ios 音頻后台播放
在按Home的情況下，后台如何播放音樂？
在Info.plist增加一項 Required backgroound modes默然是數組，在其下增加一個元素App plays audio
之后在代碼中添加：
[[AVAudioSession sharedInstance] setCategory: AVAudioSessionCategoryPlayback error: nil];
[[AVAudioSession sharedInstance] setActive:YES error: nil];
或者是下面的代碼：
AVAudioSession *session = [AVAudioSession sharedInstance];
[session setActive:YES error:nil];
[session setCategory:AVAudioSessionCategoryPlayback error:nil];11:47:36
放到初始化的中或在播放音樂前的即可。
19。數組排序
for (int j=0;j<[arr count];j++)
{
for (int i=0; i<[arr count]-1-j; i++) {
if ([[arr objectAtIndex:i] intValue]>[[arr objectAtIndex:i+1] intValue]) {
aa = [arr objectAtIndex:i+1];
[arr replaceObjectAtIndex:i+1 withObject:[arr objectAtIndex:i]];
[arr replaceObjectAtIndex:i withObject:aa];
}
}
}
或者這樣。。。。。。。。
//對數組進行排序
-(void)paixuForArray:(NSMutableArray *)_array
{
NSString *aa;
for (int j=0;j<[_array count];j++)
{
for (int i=0; i<[_array count]-1-j; i++) {
if ([[[_array objectAtIndex:i] substringWithRange:NSMakeRange(3, 4)] intValue]<[[[_array objectAtIndex:i+1] substringWithRange:NSMakeRange(3, 4)] intValue]) {
aa = [_array objectAtIndex:i+1];
[_array replaceObjectAtIndex:i+1 withObject:[_array objectAtIndex:i]];
[_array replaceObjectAtIndex:i withObject:aa];
}
}
}
}
20。獲取當前的日期，時間，星期幾
NSDate *date = [NSDate date];
NSCalendar *calendar = [NSCalendar currentCalendar];
NSDateComponents *comps;
// 年月日獲得
comps = [calendar components:(NSYearCalendarUnit | NSMonthCalendarUnit | NSDayCalendarUnit)
fromDate:date];
NSInteger year = [comps year];
NSInteger month = [comps month];
NSInteger day = [comps day];
NSLog(@"year: %d month: %d, day: %d", year, month, day);
//當前的時分秒獲得
comps = [calendar components:(NSHourCalendarUnit | NSMinuteCalendarUnit | NSSecondCalendarUnit)
fromDate:date];
NSInteger hour = [comps hour];
NSInteger minute = [comps minute];
NSInteger second = [comps second];
NSLog(@"hour: %d minute: %d second: %d", hour, minute, second);
// 周幾和星期幾獲得
comps = [calendar components:(NSWeekCalendarUnit | NSWeekdayCalendarUnit | NSWeekdayOrdinalCalendarUnit)
fromDate:date];
NSInteger week = [comps week]; // 今年的第幾周
NSInteger weekday = [comps weekday]; // 星期幾（注意，周日是“1”，周一是“2”。。。。）
NSInteger weekdayOrdinal = [comps weekdayOrdinal]; // 這個月的第幾周
NSLog(@"week: %d weekday: %d weekday ordinal: %d", week, weekday, weekdayOrdinal);
參考相關文章介紹，下面兩篇文章介紹的很像細。
http://www.2cto.com/kf/201202/118985.html
http://www.cppblog.com/walkklookk/archive/2011/09/15/155852.aspx
21。
iPhone隨機數
求隨機數的三種方法：
1. srand((unsigned)time(0));
int i = rand() % 5;
2. srandom(time(0));
int i = random() % 5;
3. int i = arc4random() % 5 (常用) ;
參考:
http://www.cocoachina.com/bbs/read.php?tid=70719&keyword=%CB%E6%BB%FA%CA%FD
http://www.cocoachina.com/bbs/read.php?tid-2977-fpage-2-toread--page-1.html
http://www.codeios.com/thread-310-1-1.html
ios編程：iPhone How-to:給導航欄貼圖
通過tintColor屬性可以定制UINavigationBar的背景顏色，但如果需要設定漸變色、甚至紋理來說，就需要貼圖了。 比較“暴力”的一種做法就是通過Category來重新實現- (void) drawRect:(CGRect)rect的實現，“暴力”是因為這種殺傷面很廣，所有項目內的UINavigationBar都會因此改變。這點在應 用中應該格外小心。
@interface UINavigationBar (ImageBackground)
@end
@implementation UINavigationBar (ImageBackground)
- (void) drawRect:(CGRect)rect {
[[UIImage imageNamed:@"bkimage.png"] drawInRect:rect];
}
@end
來源：http://blog.csdn.net/lbj05/archive/2011/04/02/6297218.aspx