一些你可能用到的代码

iPhone键盘改变颜色

只有这2种数字键盘才有效果：UIKeyboardTypeNumberPad，UIKeyboardTypePhonePad
keyboardAppearance ＝ UIKeyboardAppearanceAlert 
代码如下：

NSArray *ws = [[UIApplication sharedApplication] windows];
    for(UIView *w in ws){
        NSArray *vs = [w subviews];
        for(UIView *v in vs){
           if([[NSStringstringWithUTF8String:object_getClassName(v)]isEqualToString:@"UIKeyboard"]){
                v.backgroundColor = [UIColor redColor];
            }
        }
    }

从一个界面push到下一界面左上角返回按钮文字设置

在父viewController中如下设置：

UIBarButtonItem *backbutton = [[UIBarButtonItem alloc]init];
backbutton.title = @"返回列表";
self.navigationItem.backBarButtonItem = backbutton;

防止屏幕暗掉锁屏：

[[UIApplication sharedApplication] setIdleTimerDisabled:YES];

navigationbar的back键触发其他事件：

UIButton *back =[[UIButton alloc] initWithFrame:CGRectMake(200, 25, 63, 30)];
[back addTarget:self act
ion:@selector(reloadRowData:) forControlEvents:UIControlEventTouchUpInside];
[back setImage:[UIImage imageNamed:@"返回按钮.png"] forState:UIControlStateNormal];
UIBarButtonItem *backButtonItem = [[UIBarButtonItem alloc] initWithCustomView:back];
self.navigationItem.leftBarButtonItem = loginButtonItem;

让覆盖在下面层的视图接受触摸事件：

searchImage.exclusiveTouch = YES;//第一层
searchImage.userInteractionEnabled = NO;
myMapView.exclusiveTouch = NO;//第二层
myMapView.userInteractionEnabled = YES;

View的缩放

NSValue *touchPointValue = [[NSValue valueWithCGPoint:CGPointMake(100,100)] retain];
[UIView beginAnimations:nil context:touchPointValue];
transform = CGAffineTransformMakeScale(0.1,0.21);
firstPieceView.transform = transform;
[UIView commitAnimations]; 

去除nsstring中的空格，table 以及newline，nextline：

NSCharacterSet *whitespace = [NSCharacterSet whitespaceAndNewlineCharacterSet];
NSString *username = [mUsernameField stringValue];
username = [username stringByTrimmingCharactersInSet:whitespace];

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];

UILabel 自适应高度，自动换行

_labelName = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, IPHONE_BUTTON_WIDTH, 1000)];
        [_labelName setFont:[UIFont boldSystemFontOfSize:25]];
        [_labelName setTextColor:[UIColor whiteColor]];
        [_labelName setBackgroundColor:[UIColor colorWithRed:0 green:0 blue:0 alpha:0.6f]];
        [_labelName setNumberOfLines:0];
        [_labelName setText:NSLocalizedString(@"nameLabel", @"……")];
        [_labelName sizeToFit];
        [_labelName setFrame:CGRectMake(0, 0, IPHONE_BUTTON_WIDTH, _labelName.frame.size.height)];

一些你可能用到的代码链接：http://www.cnblogs.com/dark-angel/archive/2011/07/05/2098087.html

代码例子区全区搜索索引：http://www.cocoachina.com/bbs/read.php?tid=12269