- (UIImage *)imagecutWithRect:(CGRect)rect {

    CGImageRef subImageRef = CGImageCreateWithImageInRect(self.CGImage, rect);

    CGRect smallRect = CGRectMake(, , CGImageGetWidth(subImageRef), CGImageGetHeight(subImageRef));

    // 开启图形上下文

    UIGraphicsBeginImageContext(smallRect.size);

    CGContextRef context = UIGraphicsGetCurrentContext();

    CGContextDrawImage(context, smallRect, subImageRef);

    UIImage * image = [UIImage imageWithCGImage:subImageRef];

    // 关闭图形上下文

    UIGraphicsEndImageContext();

    CGImageRelease(subImageRef);

    return image;

}

- (UIImageView *)imageView {

    if (_imageView == nil) {

        self.imageView = [[UIImageView alloc] init];

        self.imageView.backgroundColor = [UIColor redColor];

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

        // 截取原图中间300*300

        CGFloat cutImageWH = ;

        CGFloat cutImage_x = (image.size.width - ) / ;

        CGFloat cutImage_y = (image.size.height - ) / ;

        self.imageView.image = [image imagecutWithRect:CGRectMake(cutImage_x, cutImage_y, cutImageWH, cutImageWH)];

    } return _imageView;

}