iOS 图片的截取

第一种：整个屏幕截取

在ViewController中写的，这个类是一个视图控制器

-(void)loadView{

//静态方法sharedApplication
[[UIApplication sharedApplication]setStatusBarHidden:YES //把状态栏隐藏
withAnimation:UIStatusBarAnimationSlide];
UIImage *mage=[UIImage imageNamed:@"image.png"];
UIImageView *imageView=[[UIImageView alloc]initWithFrame:[[UIScreen mainScreen]applicationFrame]];

//UIImageView *im=[UIImageView alloc]initWithImage:mage];
[imageView setImage:mage];

self.view=[[UIView alloc]initWithFrame:[[UIScreen mainScreen]applicationFrame]];
[self.view addSubview:contentView];
CGRect rect=CGRectMake(0, 0, 320, 480);
UIGraphicsBeginImageContext(rect.size);
CGContextRef currentContext=UIGraphicsGetCurrentContext();
CGContextClipToRect(currentContext,rect);
CGContextDrawImage(currentContext, rect, mage.CGImage);
UIImage *image=UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
contentView.image=image;
self.view=[[UIView alloc]initWithFrame:[[UIScreen mainScreen]applicationFrame]];
[self.view addSubview:contentView];
[image release];

}

第二种：整张图片的缩略

-(void)loadView{
[[UIApplication sharedApplication]setStatusBarHidden:YES withAnimation:UIStatusBarAnimationSlide];
UIImage *image=[UIImage imageNamed:@"image.png"];
//UIImageView *contentView=[[UIImageView alloc]initWithFrame:[[UIScreen mainScreen] applicationFrame]];

//用来控制图片缩到多大
CGRect rect=CGRectMake(0, 0, 160, 240);
UIGraphicsBeginImageContext(rect.size);
CGContextRef currentContent=UIGraphicsGetCurrentContext();
CGContextClipToRect(currentContent, rect);
[image drawInRect:rect];
UIImage *image=UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
UIImageView *contentView=[[UIImageView alloc]initWithFrame:rect];
contentView.image=image;
self.view=[[UIView alloc]initWithFrame:[[UIScreen mainScreen]applicationFrame]];
[self.view addSubview:contentView];

[image release];
}