HorizontalLayoutGroup or VerticalLayoutGroup not updating when I add new child

I am setting placing a new gameobject as a child of the layout group like so,

this.transform.SetParent(_parent);

where this is the child object and parent is the transform of the layout group. Previously this had updated, I think the layout group must have had the dirty flag set.
However this had stopped working. Now the child object is added correctly to the parent, but it's position is not updated in accordance with the layout group.

How do I prompt HorizontalLayoutGroup that there is a new child and it should update the position of all child objects?

 

@Culzean - Hi, have you checked this component:

http://docs.unity3d.com/Manual/script-ContentSizeFitter.html

 

Yup I do mean in a previous version of Unity. I would need to look through commit logs in order to figure out the exact version. I'll get a demo scene together, maybe tomorrow or the next day.

@eses I have not seen this component before, thanks I'll take a look

 

I have similar problem with general GridLayout (exists in 5.3.4 and 5.4 didn't check previous versions) - reproducible in a new scene with just canvas+panel with grid layout group. There are two cases (I suppose it's the same issue):
1) like OP wrote adding element through code doesn't set proper position in panel
2) adding elements manually in the editor doesn't set proper position for the first element until I duplicate existing element:
- after adding first element:

- after adding second element:

- after duplicating second element:


Conclusion: duplicating element in a panel enforces recomputing of positions of all elements.

Bonus question: can I somehow enforce such recompute from script?

Found using Uncle G, but doesn't work for me:
- transform.SetParent(transform, false);
- transform.localScale = Vector3.one;
- LayoutRebuilder.MarkLayoutForRebuild (transform as RectTransform);

 

Done.

 

Any update on this as I'm getting this still in 5.5.0f3?

 

Has this been fixed. Ran in to a similar issue.

 

I had the same issue by using SetParent().

Code (CSharp):

1. GameObject newGO = Instantiate(goPrefab);
2. newGo.SetParent(goParent); // doesn't update layout

To fix it instantiate de newGameObject directly inside the parent.

Code (CSharp):

1. GameObject newGO = Instantiate(goPrefab,goParent); // updates layout

 

This component not working; tried it across a few different editors and files ‍♀️

 

Still not working...