截取图片

[objc] view plaincopy

    // 从view上截图
    - (UIImage *)getImage {  

        UIGraphicsBeginImageContextWithOptions(CGSizeMake(150, 150), NO, 1.0);  //NO，YES 控制是否透明
        [self.view.layer renderInContext:UIGraphicsGetCurrentContext()];
        UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
        UIGraphicsEndImageContext();
        // 生成后的image  

        return image;
    }  

    // 根据给定得图片，从其指定区域截取一张新得图片
    -(UIImage *)getImageFromImage{
        //大图bigImage
        //定义myImageRect，截图的区域
        CGRect myImageRect = CGRectMake(70, 10, 150, 150);
        UIImage* bigImage= [UIImage imageNamed:@"mm.jpg"];
        CGImageRef imageRef = bigImage.CGImage;
        CGImageRef subImageRef = CGImageCreateWithImageInRect(imageRef, myImageRect);
        CGSize size;
        size.width = 150;
        size.height = 150;
        UIGraphicsBeginImageContext(size);
        CGContextRef context = UIGraphicsGetCurrentContext();
        CGContextDrawImage(context, myImageRect, subImageRef);
        UIImage* smallImage = [UIImage imageWithCGImage:subImageRef];
        UIGraphicsEndImageContext();
        return smallImage;
    }