Question Encapsulate bounds not correct with UI scale mode

I'm trying to encapsulate recttransforms children with a single box which works fine with a canvas with "Constant pixel size" but once I change it to "Scale with Screen Size" they are not encapsulated correctly.
Does anyone have any idea what's wrong?

Constant pixel size example


Scale with screen size


The code

Code (CSharp):

1. public class GetBounds: MonoBehaviour
2. {
3.     public List<RectTransform> rects;
4.  
5.     private void Update() {
6.         if (Input.GetKeyDown(KeyCode.D)) {
7.             CalculateBounds(GetComponent<RectTransform>(), 1);
8.         }
9.     }
10.  
11.     void CalculateBounds(RectTransform transform, float uiScaleFactor) {
12.         Bounds bounds = new Bounds(transform.position, new Vector3(transform.rect.width, transform.rect.height, 0.0f) * uiScaleFactor);
13.  
14.         foreach (RectTransform child in rects) {
15.             Bounds childBounds = new Bounds(child.position, new Vector3(child.sizeDelta.x, child.sizeDelta.y, 0.0f) * uiScaleFactor);
16.             bounds.Encapsulate(childBounds);
17.         }
18.  
19.         transform.sizeDelta = bounds.size;
20.         transform.position = bounds.center;
21.     }
22. }

 

Best way is to set the size delta to zero and instead set the anchor min / max.