基于约束的iOS Update Interface Builder视图框架

Question

I am building my views in Interface Builder and I am using AutoLayout constraints. Whenever I create a Table View Cell I use Automatic Dimension so cell's heights are calculated properly.

The problem is that cell frame in interface builder is not updating on its own (I mean the whole view's cell)

Take look at this example: I've created a cell with a label, all vertical constraints are set and they're static. Top, Bottom, Height -> 20 + 20 + 30 = 70 points

And this is fine, there are no errors in IB and cell is working. But the problem appears when I modify cell size in IB:

And errors appear causing the whole view not to behave properly. I would not like to change any of the constraints, but I'd like the whole view to shrink from that frame to frame displayed on the first photo where the frame height was 70 points.

This is a problem on bigger and more complicated views, when I change a couple of constraints and I need to update frame manually.

What do I do right now to get rid of these errors is changing the priority of the last bottom constraint to 999, that works, but I'd really like to have IB to show this view as close as possible to a view calculated in runtime.

(I know that there us 'Update frames' button, but that does indeed change the subviews frames properly, but I'd like the superview, to update too)

Aren't there any plugins or something that could help me building views that look just like at runtime?

Answer 1

This problem happens when you try to shrink the view after you set hardcoded constraints so the cesl'height is not satisfying with the current constraints, so you see red lines.

The workaround is: every time you want to change any constraint inside the cell, remove the bottom most constraint, make the change, resize the cell yourself by dragging, then reconnect it again to the bottom of the content-view.