Width is not streching to meet the contraint using AutoLayout

Question

So I'm trying to make my design stretch to full width on iphone 6, but for some reason the constraint is not doing what I want it to.

The lower arrow's width is way larger than 10.

What could the problem be and is there anything else you need to see from me to debug the problem?

The superview is a ScrollView with the horizontal scroll disabled for what its worth...

Answer 1

When using AutoLayout inside a UIScrollView, the contentSize of the scroll view is calculated based on the constraints added within the scroll view.

By the looks of things, you want the contentSize.width of your scroll view to be equal to the bounds.size.width of its superview.

To do this, you can simply add a constraint to your scroll view instructing it to constrain its width to be equal to the width of its superview.

In code, it would be something like this:

[NSLayoutConstraint constraintWithItem:self.scrollView attribute:NSLayoutAttributeWidth relatedBy:NSLayoutRelationEqual toItem:self.view attribute:NSLayoutAttributeWidth multiplier:1.0 constant:0.0];

Or in Interface Builder, you can simply hold down the Ctrl key then drag from the scroll view to its superview to add a Equal Widths constraint.