截图UIView的某个CGRect，返回图片

#import <Foundation/Foundation.h>
#import <QuartzCore/QuartzCore.h>
@interface YAScreenShotClass : NSObject
+(UIImage *)screenShotFrom:(UIView *)view frame:(CGRect)frame;
@end

#import "YAScreenShotClass.h"

@implementation YAScreenShotClass
+(UIImage *)screenShotFrom:(UIView *)view frame:(CGRect)frame
{
if(UIGraphicsBeginImageContextWithOptions != NULL)
{
UIGraphicsBeginImageContextWithOptions(frame.size, NO, 0.0);
} else {
UIGraphicsBeginImageContext(frame.size);
}

//获取图像
[view.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();

return image;
}
@end