iOS_UIImage_图片剪切

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

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

CGRect smallRect = CGRectMake(0, 0, 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 = 300;
CGFloat cutImage_x = (image.size.width - 300) / 2;
CGFloat cutImage_y = (image.size.height - 300) / 2;

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