iOS 常用代码块

1.判断邮箱格式是否正确的代码：

// 利用正则表达式验证

-( BOOL )isValidateEmail:( NSString  *)email

{

 

NSString  *emailRegex =  @"[A-Z0-9a-z._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,4}" ;

 

NSPredicate  *emailTest = [ NSPredicate   predicateWithFormat : @"SELF MATCHES%@",emailRegex];

 

return  [emailTest  evaluateWithObject :email];

}

 

2.图片压缩

 

用法： UIImage *yourImage= [self imageWithImageSimple:image scaledToSize:CGSizeMake(210.0, 210.0)];

// 压缩图片

- ( UIImage *)imageWithImageSimple:( UIImage *)image scaledToSize:( CGSize )newSize

{

// Create a graphics image context

UIGraphicsBeginImageContext (newSize);

 

// Tell the old image to draw in this newcontext, with the desired

// new size

[image  drawInRect : CGRectMake ( 0 , 0 ,newSize. width ,newSize. height )];

 

// Get the new image from the context

UIImage * newImage =  UIGraphicsGetImageFromCurrentImageContext ();

 

// End the context

UIGraphicsEndImageContext ();

 

// Return the new image.

return  newImage;

}

 

 

3.亲测可用的图片上传代码

- ( IBAction )uploadButton:( id )sender {

UIImage  *image = [ UIImage   imageNamed : @"1.jpg" ]; // 图片名

NSData  *imageData =  UIImageJPEGRepresentation (image, 0.5 );// 压缩比例

NSLog ( @" 字节数 :%i" ,[imageData length]);

// post url

NSString  *urlString =  @"http://192.168.1.113:8090/text/UploadServlet" ;

// 服务器地址

// setting up the request object now

NSMutableURLRequest  *request = [[ NSMutableURLRequest   alloc ]  init ] ;

[request  setURL :[ NSURL   URLWithString :urlString]];

[request  setHTTPMethod : @"POST" ];

//

NSString  *boundary = [ NSString   stringWithString : @"---------------------------14737809831466499882746641449" ];

NSString  *contentType = [ NSString   stringWithFormat : @"multipart/form-data;boundary=%@",boundary];

[request  addValue :contentType  forHTTPHeaderField :  @"Content-Type" ];

//

NSMutableData  *body = [ NSMutableData   data ];

[body  appendData :[[ NSString   stringWithFormat : @"\r\n--%@\r\n" ,boundary]  dataUsingEncoding: NSUTF8StringEncoding ]];

[body  appendData :[[ NSString   stringWithString : @"Content-Disposition:form-data; name=\"userfile\"; filename=\"2.png\"\r\n" ]  dataUsingEncoding : NSUTF8StringEncoding ]]; // 上传上去的图片名字

[body  appendData :[[ NSString   stringWithString : @"Content-Type: application/octet-stream\r\n\r\n"]  dataUsingEncoding : NSUTF8StringEncoding ]];

[body  appendData :[ NSData   dataWithData :imageData]];

[body  appendData :[[ NSString   stringWithFormat : @"\r\n--%@--\r\n" ,boundary] dataUsingEncoding : NSUTF8StringEncoding ]];

  [request  setHTTPBody :body];

 

// NSLog(@"1-body:%@",body);

NSLog ( @"2-request:%@" ,request);

 

NSData  *returnData = [ NSURLConnection   sendSynchronousRequest :request  returningResponse: nil   error : nil ];

NSString  *returnString = [[ NSString   alloc ]  initWithData :returnData  encoding :NSUTF8StringEncoding ];

NSLog ( @"3- 测试输出： %@" ,returnString );

 

 

4.给imageView加载图片

UIImage  *myImage = [ UIImage   imageNamed : @"1.jpg" ];

   [ imageView   setImage :myImage];

   [ self . view   addSubview : imageView ];

 

5.对图库的操作

选择相册：

UIImagePickerControllerSourceTypesourceType=UIImagePickerControllerSourceTypeCamera;

   if (![UIImagePickerControllerisSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera]) {

       sourceType=UIImagePickerControllerSourceTypePhotoLibrary;

   }

   UIImagePickerController * picker = [[UIImagePickerControlleralloc]init];

   picker.delegate = self;

   picker.allowsEditing=YES;

   picker.sourceType=sourceType;

   [self presentModalViewController:picker animated:YES];

选择完毕：

 -(void)imagePickerController:(UIImagePickerController*)pickerdidFinishPickingMediaWithInfo:(NSDictionary *)info

{

   [picker dismissModalViewControllerAnimated:YES];

   UIImage * image=[info objectForKey:UIImagePickerControllerEditedImage];

   [self performSelector:@selector(selectPic:) withObject:imageafterDelay:0.1];

}

 -(void)selectPic:(UIImage*)image

{

   NSLog(@"image%@",image); 

   imageView = [[UIImageView alloc] initWithImage:image];

   imageView.frame = CGRectMake(0, 0, image.size.width, image.size.height);

[self.viewaddSubview:imageView];

   [self performSelectorInBackground:@selector(detect:) withObject:nil];

}

detect 为自己定义的方法，编辑选取照片后要实现的效果

取消选择：

 -(void)imagePickerControllerDIdCancel:(UIImagePickerController*)picker 

{

   [picker dismissModalViewControllerAnimated:YES];

}

 

6.跳到下个View

nextWebView  = [[ WEBViewController   alloc ]  initWithNibName : @"WEBViewController"   bundle: nil ];

[ self   presentModalViewController : nextWebView   animated : YES ];

 

 

 

 

7.创建一个UIBarButton右边按钮

UIBarButtonItem  *rightButton = [[ UIBarButtonItem   alloc ]  initWithTitle : @" 右边 "   style :UIBarButtonItemStyleDone   target : self   action : @selector (clickRightButton)];

[ self . navigationItem   setRightBarButtonItem :rightButton];

 

 

8.设置navigationBar隐藏

self . navigationController . navigationBarHidden  =  YES ;//

 

9.UIlabel多行文字自动换行 （自动折行）

UIView *footerView = [[UIView alloc]initWithFrame:CGRectMake(10, 100, 300, 180)];

UILabel *label = [[UILabel alloc]initWithFrame:CGRectMake(10, 100, 300, 150)];

label.text = @"Hello world! Hello world!Hello world! Hello world! Hello world! Hello world! Hello world! Hello world!Hello world! Hello world! Hello world! Hello world! Hello world! Helloworld!";

// 背景颜色为红色

label.backgroundColor = [UIColor redColor];

// 设置字体颜色为白色

label.textColor = [UIColor whiteColor];

// 文字居中显示

label.textAlignment = UITextAlignmentCenter;

// 自动折行设置

label.lineBreakMode = UILineBreakModeWordWrap;

label.numberOfLines = 0;

 

 

10.代码生成Button

CGRect  frame =  CGRectMake ( 0 ,  400 ,  72.0 ,  37.0 );

UIButton  *button = [ UIButton   buttonWithType : UIButtonTypeRoundedRect ];

button. frame  = frame;

[button  setTitle : @" 新添加的按钮 "  forState:  UIControlStateNormal ];

button. backgroundColor  = [ UIColor   clearColor ];

button. tag  =  2000 ;

[button  addTarget : self   action : @selector (buttonClicked:)  forControlEvents :UIControlEventTouchUpInside ];

[ self . view   addSubview :button];

10.2在xib文件中已经创建好Button，通过tag获取按钮

UIButton *testButton= (UIButton*)[self.view viewWithTag:100];
    [testButton addTarget:self action:@selector(test:) forControlEvents:UIControlEventTouchUpInside];

//按钮事件

-(void) test: (id) sender{
    UIAlertView *av = [[[UIAlertView alloc] initWithTitle:@"ceshi" message:@"test11111" delegate:nil cancelButtonTitle:@"OK"otherButtonTitles:nil] autorelease];
    [av show];
}

11.让某个控件在View的中心位置显示：

（某个控件，比如 label ， View ） label . center  =  self . view . center；

 

12.自定义text各种效果：

cell.backgroundColor = [UIColorscrollViewTexturedBackgroundColor];
// 设置文字的字体 
cell.textLabel.font = [UIFont fontWithName:@"AmericanTypewriter" size:100.0f];
// 设置文字的颜色 
cell.textLabel.textColor = [UIColor orangeColor];
// 设置文字的背景颜色 
cell.textLabel.shadowColor = [UIColor whiteColor];
// 设置文字的显示位置 
cell.textLabel.textAlignment = UITextAlignmentCenter;

 

13.隐藏statusBar： 
在程序的 viewDidLoad 中加入 

[[UIApplication sharedApplication]setStatusBarHidden:YES animated:NO];

 

14.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 = [UIImageimageNamed:@"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)];// 这个地方的大小要自己调整，以适应 alertview 的背景颜色的大小。 
   theImage = UIGraphicsGetImageFromCurrentImageContext();    
UIGraphicsEndImageContext(); 
   theAlert.layer.contents = (id)[theImage CGImage];

 

15.键盘透明： 
textField.keyboardAppearance = UIKeyboardAppearanceAlert;

16.状态栏的网络活动风火轮是否旋转： 
[UIApplication sharedApplication].networkActivityIndicatorVisible ， 默认值是 NO 。

 

17.截取屏幕图片： 
// 创建一个基于位 图的图形上下文并指定大小为CGSizeMake(200,400)
UIGraphicsBeginImageContext(CGSizeMake(200,400));

//renderInContext  呈现接受者及其子范围到 指定的上下文
[self.view.layer renderInContext:UIGraphicsGetCurrentContext()];
    // 返回 一个基于当前图形上下文的图片
 UIImage *aImage = UIGraphicsGetImageFromCurrentImageContext();
  // 移除栈顶 的基于当前位图的图形上下文
UIGraphicsEndImageContext();
// 以 png 格式 返回指定图片的数据
imageData = UIImagePNGR epresentation(aImage);

 

18.更改cell选中的背景： 
    UIView *myview = [[UIView alloc] init];
    myview.frame = CGRectMake(0, 0, 320, 47);
    myview.backgroundColor = [UIColorcolorWithPatternImage:[UIImage imageNamed:@"0006.png"]];
    cell.selectedBackgroundView = myview;:

 

19.显示图片：

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];

 

20.能让图片适应框的大小（beta）

NSString*imagePath = [[NSBundle mainBundle] pathForResource:@"XcodeCrash"ofType:@"png"];    
    UIImage *image = [[UIImage alloc]initWithContentsOfFile:imagePath]; 
        UIImage *newImage= [image transformWidth:80.f height:240.f]; 
    UIImageView *imageView = [[UIImageView alloc]initWithImage: newImage]; 
         [newImagerelease]; 
    [image release]; 
    [self.view addSubview:imageView];

 

 

21. 实现点击图片进行跳转的代码：（生成一个带有背景图片的button，给button绑定想要的事件）

UIButton *imgButton=[[UIButton alloc]initWithFrame:CGRectMake(0, 0, 120, 120)];

[imgButton setBackgroundImage:(UIImage *)[self.imgArray objectAtIndex:indexPath.row] forState:UIControlStateNormal];

imgButton.tag=[indexPath row];

[imgButton addTarget:self action:@selector(buttonClick:) forControlEvents:UIControlEventTouchUpInside];

 

22.键盘回收：

1).增加一个button，相应touch down事件，隐藏键盘。这种方法，太山寨了。为了相应一个事件增加一个button太不值得的。

.h

- (IBAction)dismissKeyBoard:(id)sender;

.m

- (IBAction)dismissKeyBoard:(id)sender {

[testText resignFirstResponder];

}

 

2).第二种方法：在背景图片上添加Tap事件，相应单击处理。这种方法，很好代替了button方式，但是如果UI上没有背景图片，这种方法又回到到第一种山寨的方法行列中。

// 添加带有处理时间的背景图片

UIImageView *backView = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, self.view.bounds.size.width, self.view.bounds.size.height)];

backView.image = [UIImage imageNamed:@"small3.png"];

backView.userInteractionEnabled = YES;

UITapGestureRecognizer *singleTouch = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(dismissKeyboard:)];

[backView addGestureRecognizer:singleTouch];

backView.tag = 110;

[self.view addSubview:backView];

 

-(void)dismissKeyboard:(id)sender{

[text resignFirstResponder];

}

3).在xib文件中，修改xib文件的objects属性，默认是view属性，我们可以修改为UIControl属性，从而是xib文件相应touch down事件。这种方法，缺点就是没有xib就悲剧了。

.h

- (IBAction)dimissKeyboard:(id)sender;

.m

- (IBAction)dimissKeyboard:(id)sender {

[text resignFirstResponder];

}

23、Gif图片的解析

//加载gif

NSString *filePath = [[NSBundle mainBundle]pathForResource:@"bai3" ofType:@"gif"];

NSData *data = [NSData dataWithContentsOfFile:filePath];

CGImageSourceRef gif = CGImageSourceCreateWithData((CFDataRef)data, nil);

//获取gif的各种属性

CFDictionaryRef gifprops =(CGImageSourceCopyPropertiesAtIndex(gif,0,NULL));

NSLog(@"_______%@",gifprops);

NSInteger count =CGImageSourceGetCount(gif);

NSLog(@"________%d",count);

CFDictionaryRef gifDic = CFDictionaryGetValue(gifprops, kCGImagePropertyGIFDictionary);

CFDictionaryRef delay = CFDictionaryGetValue(gifDic, kCGImagePropertyGIFDelayTime);

NSLog(@"_______%@",delay);

//[gifDic objectForKey:(NSString *)kCGImagePropertyGIFDelayTime];

//    NSNumber * w = CFDictionaryGetValue(gifprops, @"PixelWidth");

//    NSNumber * h =CFDictionaryGetValue(gifprops, @"PixelHeight");

//    float totalDuration = delay.doubleValue * count;

//    float pixelWidth = w.intValue;

//    float pixelHeight = h.intValue;

//将gif解析成UIImage类型对象，并加进images数组中

NSMutableArray *images = [NSMutableArray arrayWithCapacity:count];

for(int index=0;index<count;index++)

{

CGImageRef ref = CGImageSourceCreateImageAtIndex(gif, index, nil);

UIImage *img = [UIImage imageWithCGImage:ref];

[images addObject:img];

CFRelease(ref);

}

CFRelease(gifprops);

CFRelease(gif);

Gif的合成

- (void)exportAnimatedGif:(CGImageSourceRef )gif :(NSMutableArray *)images

{

NSString *path = [[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject] stringByAppendingPathComponent:@"animated.gif"];

CGImageDestinationRef destination = CGImageDestinationCreateWithURL(( CFURLRef)[NSURL fileURLWithPath:path],

kUTTypeGIF,

images.count,

NULL);

UIImage *image;

for (int i = 0; i<images.count; i++)

{

image = images[i];

CFDictionaryRef gifprops =(CGImageSourceCopyPropertiesAtIndex(gif,i,NULL));

CFDictionaryRef gifDic = CFDictionaryGetValue(gifprops, kCGImagePropertyGIFDictionary);

NSNumber *delay = CFDictionaryGetValue(gifDic, kCGImagePropertyGIFDelayTime);

NSDictionary *gifDelay = [NSDictionary dictionaryWithObject:[NSDictionary dictionaryWithObject:delay forKey:(NSString *)kCGImagePropertyGIFDelayTime]

forKey:(NSString *)kCGImagePropertyGIFDictionary];

CGImageDestinationAddImage(destination,image.CGImage, (CFDictionaryRef)gifDelay);

CGImageDestinationSetProperties(destination, ( CFDictionaryRef)gifprops);

}

//    CGImageDestinationSetProperties(destination, ( CFDictionaryRef)gifprops);

CGImageDestinationFinalize(destination);

CFRelease(destination);

NSLog(@"animated GIF file created at %@", path);

}

24.将一个UIView对象的内容保存为UIImage

+ (UIImage*)imageFromView:(UIView*)view{

UIGraphicsBeginImageContextWithOptions(view.bounds.size, YES, view.layer.contentsScale);

[view.layer renderInContext:UIGraphicsGetCurrentContext()];

UIImage *image = UIGraphicsGetImageFromCurrentImageContext();

UIGraphicsEndImageContext();

return image;

}

注意：生成的图片的scale和view的scale一致，这样才可以保证图片的效果和view显示的完全一致，使用renderInContext方法可以让subviews的内容也显示的图片里。

25.捕捉屏幕截图
CALayer实例使用Core Graphics的renderInContext方法可以将视图绘制到图像上下文中以便转化为其他UIImage实例。前提先#import <QuartzCore/QuartzCore.h>

+ (UIImage *) imageFromView: (UIView *)theView {
    // draw a view's contents into an image context
   UIGraphicsBeginImageContext(theView.frame.size);
   CGContextRef  context = UIGraphicsGetCurrentContext();

   [theView.layer  renderInContext:context];
   UIImage *theImage = UIGraphicsGetImageFromCurrentImageContext();
   UIGraphicsEndImageContext(); 
   return theImage;
}

注：UIGraphicsBeginImageContext(CGSize size)创建一个基于位图的上下文(context)，并将其设置为当前上下文。函数功能与UIGraphicsBeginImageContextWithOptions相同，相当于该方法的opaque参数为NO，scale因子为1.0。而UIGraphicsEndImageContext()方法是移除栈顶的基于当前位图的图形上下文。

26.捕捉截取某个区域内屏幕图像

- (UIImage *)imageFromView: (UIView *) theView  atFrame:(CGRect)rect
{
    UIGraphicsBeginImageContext(theView.frame.size);
    CGContextRef context = UIGraphicsGetCurrentContext();
    CGContextSaveGState(context);
    UIRectClip(rect);
    [theView.layer renderInContext:context];
    UIImage *theImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    return  theImage;//[self getImageAreaFromImage:theImage atFrame:rect];
}

27.从某图片中截图

UIImage *image = [[UIImage alloc] initWithData:data];//大图
CGRect imageRect = CGRectMake(0.0, 0.0, image.size.width, image.size.height);
CGSize itemSize = CGSizeMake(w,h);
UIGraphicsBeginImageContext(itemSize);
[image drawInRect:imageRect];
UIImage *smallimage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext(); 

28.视图添加倒影效果

const CGFloat kReflectPercent = -0.25f;
const CGFloat kReflectOpacity = 0.3f;
const CGFloat kReflectDistance = 10.0f;

+ (void)addSimpleReflectionToView:(UIView *)theView
{
     CALayer *reflectionLayer = [CALayer layer];
     reflectionLayer.contents = [theView layer].contents;
     reflectionLayer.opacity = kReflectOpacity;
     reflectionLayer.frame = CGRectMake(0.0f,0.0f,theView.frame.size.width,theView.frame.size.height*kReflectPercent);  //倒影层框架设置，其中高度是原视图的百分比
    CATransform3D stransform = CATransform3DMakeScale(1.0f,-1.0f,1.0f);
     CATransform3D transform = CATransform3DTranslate(stransform,0.0f,-(kReflectDistance + theView.frame.size.height),0.0f);
     reflectionLayer.transform = transform;
     reflectionLayer.sublayerTransform = reflectionLayer.transform;
     [[theView layer] addSublayer:reflectionLayer];
}

另一：使用Core Graphics创建倒影

+ (CGImageRef) createGradientImage:(CGSize)size
{
      CGFloat colors[] = {0.0,1.0,1.0,1.0};
      //在灰色设备色彩上建立一渐变
     CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceGray();
      CGContextRef context = CGBitmapContextCreate(nil,size.width,size.height,8,0,colorSpace,kCGImageAlphaNone);
      CGGradientRef gradient = CGGradientCreateWithColorComponents(colorSpace,colors,NULL,2);
      CGColorSpaceRelease(colorSpace);

      //绘制线性渐变
     CGPoint p1 = CGPointZero;
      CGPoint p2 = CGPointMake(0,size.height);
      CGContextDrawLinearGradient(context,gradient,p1,p2,kCGGradientDrawsAfterEndLocation);

      //Return the CGImage
      CGImageRef theCGImage = CGBitmapContextCreateImage(context);
      CFRelease(gradient);
      CGContextRelease(context);
      return theCGImage;
}

//Create a shrunken frame for the reflection

+ (UIImage *) reflectionOfView:(UIView *)theView WithPercent:(CGFloat) percent
{
     //Retain the width but shrink the height
     CGSize size = CGSizeMake(theView.frame.size.width, theView.frame.size.height * percent);

     //Shrink the View
     UIGraphicsBeginImageContext(size);
     CGContextRef context = UIGraphicsGetCurrentContext();
     [theView.layer renderInContext:context];
     UIImage *partialimg = UIGraphicsGetImageFromCurrentImageContext();
     UIGraphicsEndImageContext();

     //build the mask
     CGImageRef mask = [ImageHelper createGradientImage:size];
     CGImageRef ref = CGImageCreateWithMask(partialimg.CGImage,mask);
     UIImage *theImage = [UIImage imageWithCGImage:ref];
     CGImageRelease(ref);
     CGImageRelease(mask);
     return theImage;
}

const CGFloat kReflectDistance = 10.0f;
+ (void) addReflectionToView: (UIView *)theView
{
     theView.clipsToBounds = NO;
     UIImageView *reflection = [[UIImageView alloc] initWithImage:[ImageHelper reflectionOfView:theView withPercent:0.45f]];
     CGRect frame = reflection.frame;
     frame.origin = CGPointMake(0.0f, theView.frame.size.height + kReflectDistance);
     reflection.frame = frame;

     // add the reflection as a simple subview
     [theView addSubView:reflection];
     [reflection release];
}

29.实现圆角图片：

UIColor *color = [UIColor colorWithRed:0.95 green:0.95 blue:0.95 alpha:0];
[aImage setBackgroundColor:color]; //设置背景透明

/******设置图片圆角begin*******/
aImage.layer.masksToBounds = YES;
aImage.layer.cornerRadius = 5.0;
aImage.layer.borderWidth = 0.5;
aImage.layer.borderColor = [[UIColor grayColor] CGColor];
/******设置图片圆角end********/

另有方法可见：http://www.4ucode.com/Study/Topic/2058289转载文章。

30.实现iPhone图标的水晶立体效果

- (void)viewDidLoad {
    [super viewDidLoad];
    UIGraphicsBeginImageContext(icon.bounds.size);
    CGContextRef ctx = UIGraphicsGetCurrentContext();
    const CGFloat components[4] = {0.0,0.4,0.0,1.0};
    CGContextSetFillColor(ctx, components);
    CGContextFillRect(ctx, CGRectMake(0, 0, icon.bounds.size.width, icon.bounds.size.height));
    UIImage *background = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    UIImage *image = [UIImage imageNamed:@"icon.png"];
    UIImage *mask = [UIImage imageNamed:@"IconBase.png"];
    UIImage *roundCorner = [UIImage imageNamed:@"round-corner.png"];
    icon.image = image;
    CALayer* subLayer = [[CALayer layer] retain];
    subLayer.frame = icon.bounds;
    subLayer.contents = (id)[background CGImage];
    CALayer* maskLayer = [[CALayer layer] retain];
    maskLayer.frame = icon.bounds;
    maskLayer.contents = (id)[mask CGImage]; 
    [subLayer setMask:maskLayer];
    [[icon layer] addSublayer:subLayer];
    CALayer* roundCornerLayer = [[CALayer layer] retain];
    roundCornerLayer.frame = icon.bounds;
    roundCornerLayer.contents = (id)[roundCorner CGImage];
    [[icon layer] setMask:roundCornerLayer];
    [maskLayer release];
    [subLayer release];
    [roundCornerLayer release];
}

31.两图合成一图

- (UIImage*)addImage:(UIImage *)image1 toImage:(UIImage*)image2
{
    UIGraphicsBeginImageContext(image1.size);

    [image1 drawInRect:CGRectMake(0,0,image1.size.width,image1.size.height)];
    [image2 drawInRect:CGRectMake(0,0,image2.size.width,image2.size.height)];

    UIImage *resultingImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return resultingImage;
}

参考链接

1.http://www.cnblogs.com/lovecode/archive/2011/11/12/2246421.html

2.http://my.oschina.net/u/819843/blog/98574