How to split UIView into equal parts using autolayout?
- Place your view.
- Place and position your three subviews with each taking one third of the width.
- Select all three subviews by holding cmd and clicking on each.
- Go Editor > Pin > Widths Equally
Make sure you set constraints for subview x and y position. In your case, you'd pin leading space of the most left subview to superview, and trailing space of your most right subview to superview ( Editor > Pin > Leading/Trailing space to superview) and vertical spacing depending on your case.
Equal width / height constraints will do this for you.
In visual format, the constraints would be:
|[view1][view2(==view1)][view3(==view1)]|
The left one is pinned to the left of the superview, the right one is pinned to the right, the centre one is pinned to the two outer ones and all three are made to be equal widths.