Incorrect UITableViewCell height UIImageView

Question

I have a UITableViewCell that only contains a UIImageView. I am using UITableViewAutomaticDimension which is working perfectly for all the other cells in my tableview, except for this image view cell.

 tableView.estimatedRowHeight = 100
 tableView.rowHeight = UITableViewAutomaticDimension

I want the image to be as tall as it wants, maintain the image's aspect ratio and fill the width. To do that I set the image view's constraints to be pinned to the cell's frame using auto layout and I set the image views contentMode to be Aspect Fit. I set the UIImageView's background to be red. And the cell above it is white. The actual image is black down below.

When I do that, the cell has about 100 px above the image and 100px below. but the images size is exactly what I want. Has anyone had the same issue?

Because that red space isn't always the same size and it was a lot taller when I have a really big image in there, I believe the layout thinks the height should be the actual height of the image, without any aspect fit constraint.

Thanks for any help!

Answer 1

I want the image to be as tall as it wants, maintain the image's aspect ratio and fill the width. To do that I set the image view's constraints to be pinned to the cell's frame using auto layout and I set the image views contentMode to be Aspect Fit.

You can't do all that with only auto layout. This is because a UIImageView's intrinsic content size is just its image's full size.

Instead, calculate the appropriate height and set it when you set your image:

let imageViewWidth : CGFloat = // the width you want…
imageHeightConstraint.constant = image.size.height / image.size.width * imageViewWidth;

Note that this will fail if you have a 0x0 image due to division by zero. If that's possible in your app, check for this case and just set the height constant to 0.

At this point, reload the row so that the table view will recalculate the height.