ios - UIImage 长宽比填充

Question

我正在尝试对 UIImage 执行方面填充(具有可重用扩展)，但我只做到了这一点:

extension UIImage {
    func resizeToCircleImage(targetSize: CGSize, contentMode: UIViewContentMode) -> UIImage {
        UIGraphicsBeginImageContextWithOptions(targetSize, true, 0.0)
        let rect = CGRect(x: 0, y: 0, width: targetSize.width, height: targetSize.height)
        self.draw(in: rect)
        let newImage = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        return newImage!
    }
}

所以，这是针对 MKAnnotationView 的。

它最终看起来像这样:

但我想与这张图片相匹配:

https://en.wikipedia.org/wiki/Panorama#/media/File:Panorama_of_the_courtyard_of_the_Great_Mosque_of_Kairouan.jpg

Answer 1

考虑 UIImage 的一个类别，

- (UIImage *)aspectFillToSize:(CGSize)size
{
    CGFloat imgAspect = self.size.width / self.size.height;
    CGFloat sizeAspect = size.width/size.height;

    CGSize scaledSize;

        if (sizeAspect > imgAspect) { // increase width, crop height
            scaledSize = CGSizeMake(size.width, size.width / imgAspect);
        } else { // increase height, crop width
            scaledSize = CGSizeMake(size.height * imgAspect, size.height);
        }
    UIGraphicsBeginImageContextWithOptions(size, NO, 0.0f);
    CGContextRef context = UIGraphicsGetCurrentContext();
    CGContextClipToRect(context, CGRectMake(0, 0, size.width, size.height));
    [self drawInRect:CGRectMake(0.0f, 0.0f, scaledSize.width, scaledSize.height)];
    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return image;
}