iPhone:在 AspectFt 之后获取图像的大小 [英] iPhone : Getting the size of an image after AspectFt

问题描述

卡住真的很奇怪，但我很奇怪.

Real odd one to get stuck on but weirdly I am.

你有一个包含图像的 imageView.你缩小 imageView 的大小，然后告诉它使用 UIViewContentModeScaleAspectFit.所以您的 imageView 可能是 300 x 200，但您的缩放图像可能是 300 x 118 或 228 x 200，因为它的 aspectfit.

You you have a imageView containing a image. You size that imageView down and then tell it to use UIViewContentModeScaleAspectFit. so your imageView might be 300 by 200 but your scaled image within could be 300 by 118 or 228 by 200 because its aspectfit.

究竟如何获得实际图像的大小?
imageView.image.size 是原始图像的大小.
imageview.frame 是 imageview 的框架，而不是包含的图像.
imageview.contentstretch 也不起作用

How on earth do you get the size of the actual image?
imageView.image.size is the size of the original image.
imageview.frame is the frame of the imageview not the contained image.
imageview.contentstretch does not work either

推荐答案

我在 UIImageView 上写了一个快速分类来实现:

I have written a quick category on UIImageView to achieve that:

(.h)

@interface UIImageView (additions)
- (CGSize)imageScale;
@end

(.m)

@implementation UIImageView (additions)
- (CGSize)imageScale {
    CGFloat sx = self.frame.size.width / self.image.size.width;
    CGFloat sy = self.frame.size.height / self.image.size.height;
    CGFloat s = 1.0;
    switch (self.contentMode) {
        case UIViewContentModeScaleAspectFit:
            s = fminf(sx, sy);
            return CGSizeMake(s, s);
            break;

        case UIViewContentModeScaleAspectFill:
            s = fmaxf(sx, sy);
            return CGSizeMake(s, s);
            break;

        case UIViewContentModeScaleToFill:
            return CGSizeMake(sx, sy);

        default:
            return CGSizeMake(s, s);
    }
}
@end

将原始图像大小乘以给定的比例，您将得到实际显示的图像大小.

Multiply the original image size by the given scale, and you'll get your actual displayed image size.

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