Setting ScrollRect normalizedPosition immediately after adding content

Hello

I'm having a peculiar issue with setting ScrollRect normalizedPosition. In general cases, if I'm just setting normalizedPosition and nothing else, it works perfectly fine, but I have a situation where I have 2 'tabs', when clicking on a tab, the contents of the ScrollRect are destroyed, and different items are loaded. I want to remember the ScrollRect's normalizedPosition for each tab, and re-set them when going back and forth between tabs

So in pseudocode, the logic is like this:

Code (CSharp):

1. void PressTabOneButton()
2. {
3.    DestroyAllContents();
4.    LoadUpNewContents();
5.    scrollRect.horizontalNormalizedPosition = 0.5f; //Just as a test value
6. }

What should happen there is when I switch tabs, the ScrollRect should be set to the middle but what is actually happening is the normalizedValue ends up being some other value.

Looks like by the time I get to setting the normalizedPosition, the Scroll Rect isn't quite 'ready' yet, so it sets the position to 0.5f for 1 frame, and then in the next frame it 'jumps' to some other value.

I think what's happening is the layouts haven't fully rebuilt yet by this time, perhaps it only finishes rebuilding everything by the next frame? So I turned this into a Coroutine and waited 1 frame before setting the normalizedPosition. 1 frame doesn't work, but strangely enough waiting 2 frames does work!

I really don't think having to wait 2 frames is ideal, so I was wondering if there's some other way to make this work properly all in the same frame? I have tried ALL SORTS of possible things just before setting the normalizedPosition, including:

• Canvas.ForceUpdateCanvases()

• CalculateLayoutInputVertical()

  and

  SetLayoutHorizontal()

• set enabled = false and back to true again

• LayoutRebuilder.ForceRebuildLayoutImmediate()

All these result in the normalizedPosition to jump to strange values I don't understand.

How can I make this work in the same frame right after adding content to the ScrollRect?

 

Yep, hit this exact same annoying problem. So hard to work with.