UIImageView约束是1：1长宽比和1：1缩放到原始比例吗？

Question

Is there any simple way to achieve a 1:1 aspect ratio and scale to the original image inside an ImageView ?

I don't want only to keep the Image aspect ratio, I want it to be exactly the same size as the underlying image (1:1 scale also to original)... not smaller, not bigger... so it will be 1:1 on screen in therms of pixels or UIKit points or w/e with the original (scaling 1).

If you only set aspect ratio, the image might scale up or down, whilst keeping aspect ratio. I want to prevent this behaviour and to tell it not to scale.

How can I set the scale to be 1 as a constraint ? Is there any way in doing this, without any hardcoding on width / height constraints to match the size of the original image ?

Basically I want to tell the autolayout... here is the image, don't touch it, never scale it no matter what, let it be exactly as the original (scaling 1).

UPDATE:

The only way I could achieve this is by setting the hugging / compression priorities to higher than other items in the layout. Only setting aspect ratio constraint doesn't do it... I think there is no other way to ensure this behaviour without touching compression / hugging priorities.

Answer 1

Set the contentMode to aspectFit .

See Apple official documentation :

The option to scale the content to fit the size of the view by maintaining the aspect ratio. Any remaining area of the view's bounds is transparent.

Answer 2

Don't put any height or aspect ratio constraint to your UIImageView just put the width constraint or leading and trailing constraint whatever suits your need. And make contentMode AspectFill .

ImageView will scale automatically to match the aspect ratio of the image it holds. However make sure to have a height <= the maximum height you should have(In the images below I should put height <= the screen height) so that the image doesn't go beyond the desired bounds.

Answer 3

Try setting the ContentMode of your ImageView as Center .

Also remember to set clip to bounds.

imageView.clipsToBounds = true
imageView.contentMode = .center