UIStackView 分布，一个子视图的内在内容大小优先

Question

  stackView
+------------+                +
|  topView   | height: 50     |
+------------+                |
|            |                |
|            |                | total height: 300
| bottomView | height: 250    |
|            |                |
|            |                |
+------------+                +

I would like to layout two views ( topView and bottomView ) in a UIStackView ( stackView ) with these conditions:

• stackView has a height (let's say 300)
• topView 's and bottomView 's intrinsic content height is the same (let's say 50)
• topView 's should be rendered with its intrinsic content height (up to stackView 's height) (so 50)
• bottomView should take the remaining space (so 250)
• if topView 's intrinsic content height changes (let's say to 100) the distribution should be 100/200

None of the distribution modes of UIStackView can cover this.

Setting a constraint with a constant wouldn't help here, as the intrinsic content height of topView might change.

So I need some Auto Layout features here. I tried setting different content compression resistance priorities and content hugging priorities. Without success, I still feel like they could be a solution (if I knew how to use them correctly).

It doesn't seem like a complex problem, I can't find the right Auto Layout API for this. Any hints?

Answer 1

You should set:

• vertical content hugging priority of top view to be more than bottom view
• alignment of stack view to fill
• distribution of stack view to fill

You should add a width constraint as well, if the top and bottom views do not have intrinsic width.

Demo: