Resize UIImageView after Scale Aspect Fit

5
votes

I have a UITableViewCell containing only a UIImageView that is constrained to the superview on all four sides so that the cell scales to fit the full image.

The UIImageView is set to Scale Aspect Fit so that the large images resize to fit within the width of the cell. However, after the aspect fit takes place, the UIImageView remains the same size as before the scaling, and the cell in turn retains the size of the larger, unscaled image.

Is there any way in Interface Builder to force the height of the UIImageView to scale down when the image is scaled down by the Fit property? Or, equally, is there any way to programmatically tell the UIImageView to resize its height to match the newly scaled UIImage height?

1
iosswiftuiimageview
At the moment I have abandoned auto layout for the resizing and built the resizing code myself, which is no more than a few lines. However it seems that the climate is such that it is preferable to use auto layout where possible and so the question still stands. – Dom Vinyard
Hey! I know it has been a while since you posted this, but could you please share your programmatic solution? It would be helpful if you could edit your question to show this. Thanks! – Pranav Wadhwa
I'm afraid I'm no longer involved in that project, hopefully someone else will step in. – Dom Vinyard

1 Answers

3
votes

I encountered similar problem while embedding UIImageView into UIStackView. I consider this a bug because when image view has Mode:AspectFit then unbound dimension expected to resize to the scaled image instead of original.

My workaround was:

  1. created height constraint with identifier for the image view, e.g. "constraintImageHeight"

  2. in the code after putting a new image into the view, the constraint is reset to calculated height, e.g.:

    imgView.image = picture; for c in imgView.constraints { if c.identifier == "constraintImageHeight" { c.constant = picture.size.height * imgView.bounds.width / picture.size.width; break; } }