使用AutoLayout动态布局scrollview contentSize

Question

I have a simple case: I have the following views hierarchy:

1. View
   1. ScrollView
      1. View
         1. Label

My label is positioned at the bottom of it's super view, and it's height is changed dynamically, depending ot the size of the text that it is rendering.

My aim is to adjust the label size depending on the text, so that no text is truncated, and with the growth of the lines of the label, to grow the scrollview's content size, so that the label always is positioned at the bottom.

How can I do that with autolayouts, preferably from IB only?

Answer 1

If you want the UILabel to stick at the bottom of its parent UIView using autolayout, then that view won't expand its height when the UILabel height increase, what really happens is that the UILabel will move up to occupy more area.

I f you wish your UIView to expand, then don't use autolayout in that UIView, and position your UILabel at a constant origin, then change the view's height & the scrollview height as per the UILabel text.

you can get the UILabel size using the below line of code:

CGSize expectedLabelSize = [yourString sizeWithFont:yourLabel.font 
                        constrainedToSize:maximumLabelSize 
                        lineBreakMode:yourLabel.lineBreakMode];