How do I programmatically change an image in an existing UIImageView and make it fit inside the image view's constraints?

Question

I have a UIImageView and when I set an image in that view using IB, the image is the correct size when I run the app (40x40). When I programmatically change the image using the code below, the new image is 400x400 or so. This is using the same image that I know works fine if it's set in IB. Do I have to scale the image before I add it to the UIImageView? I assumed auto-layout's constraints would automatically do this for me.

UIImage *messageTypeImage = [UIImage imageNamed:message.imageName];
[messageCell.imageView setImage:messageTypeImage];
[messageCell.contentView layoutIfNeeded];

The UIImageView's content mode is set to "Scale To Fill" and I've tried adding the code below both before and after calling setImage:

[messageCell.imageView setContentMode:UIViewContentModeScaleAspectFill];
[messageCell.imageView setClipsToBounds:YES];

Here's how the constraints are set up for the image view:

enter image description here

Jessamaphone, thanks for the suggestion but I'm already calling [messageCell.contentView layoutIfNeeded]; I've updated the question to reflect that. — Chris Williams, Jan 24 '15 at 21:51
What is you view Mode (i.e. contentMode) value? Scale to Fill? — vacawama, Jan 24 '15 at 22:24
Which constraints do you have set on the imageView in IB? Do you have width and height constraints? Or do you have constraints on all four sides of the imageView? — vacawama, Jan 24 '15 at 23:10
So, your image is showing up on screen as larger than 40x40? — vacawama, Jan 24 '15 at 23:44
vacawama, yes, the image shows as its native size, it's not scaled to fit at all. The same image looks fine (40x40) if I set it in IB and not programatically. — Chris Williams, Jan 25 '15 at 00:25

score 0 · Answer 1 · answered Jan 25 '15 at 00:53

Are you using iOS 8 SDK? If so, try overriding layoutSubviews in your cell subclass and add this:

   self.contentView.frame = self.bounds;
   self.contentView.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;

There are some problems with the contentViews' of collection view/table view cells constraints/masks.

score 0 · Answer 2 · edited May 23 '17 at 10:26

0

Wow. Finally found the answer here. Turns out, there's a default imageView outlet in prototype cells. I was unknowingly using that outlet and not the UIImageView I thought I was using.

edited May 23 '17 at 10:26

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answered Jan 25 '15 at 01:02

Chris Williams

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How do I programmatically change an image in an existing UIImageView and make it fit inside the image view's constraints?

2 Answers2