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