Runtime companion script, how to hook up?

How do I hook up a runtime UI Document to a companion script? I just want use C# to dynamically change some labels, but do not know how to get the root of a UI Document already in the scene to drag. VisualTreeAssets and VisualElements cannot be draggedd

 

You can access the root via

rootVisualElement

property of the

UIDocument

component. BTW, if you make a public VisualTreeAsset property, it actually displays the reference slot in the inspector and you can drag in UXML file there.

 

But the UXML file is not the instance that's created already right? Or am I misunderstanding this?

Also I cannot find UIDocument in C# as it is a sealed class, am I doing this wrong, thanks

 

The instance that is already created is accessible from the UIDocument's rootVisualElement property as I already described.

Regarding the UI Document - have you already attached the UI Document (and UI Toolkit event system) component to a GameObject in your scene? If you have, then you can attach your companion script to the same GameObject and just call

GetComponent<UIDocument>().rootVisualElement

from your script to get the instance of the UXML you attached to the UIDocument.

 

I get "The type or namespace name 'UIDocument' could not be found (are you missing a using directive or an assembly reference?) " - what is the namespace?

 

I'm on UIBuilder 1.0.0-preview.6 UI Toolkit 1.0.0-preview.8

 

I opened UIToolkitUnityRoyaleRuntimeDemo and it is as you described, any idea on how to add this to an existing project? seems like some prereq is missing

 

I tried adding this to my asmdef: "UnityEngine.UIElementsGameObjectsModule.dll", but still no good

 

The namespace is simply UnityEngine.UIElements. Simple using directive and adding that to asmdef should do the trick.

 

Yes, seems like that does not do it for me, though it works for a newly created project, I might have some conflicting setup

 

I added the following to the asmdef and it works, thanks:

"UnityEngine.UIElementsModule",
"UnityEngine.UIElementsGameObjectsModule",
"UnityEngine"

 

If you need to access the

UIDocument

component from a script on a different GameObject what is the best approach?

I could create and assign a tag to my GameObject that contains the

UIDocument

and then do

GameObject.FindWithTag("tag")

and then call GetComponent on that but I don't know if there's a more sensible approach?

 

Fair comments. Thanks for the tips!

 

When trying to

Code (CSharp):

1. GetComponent<UIDocument>();

I'm also getting or namespace not found error from a script inside an assembly I created.

I had to reference the assembly UnityEngine.UIElementsGameObjectsModule.

it sounds like this isn't intended?

Also, it's very strange that you install a package called UIToolkit, but have to make using statements and assembly references for something called UIElements. A bit counter-intuitive.

I'm on 2020.2, up to date as of today with UI builder and UItoolkit up to date as well..

Edit: Also, just wanted to say that my using statements didn't need to be changed:

Code (CSharp):

1. using System;
2. using System.Collections.Generic;
3. using UnityEngine;
4. using UnityEngine.UIElements;

This is same as before. It was the assembly reference that fixed the error

 

I also had to manually add `UnityEngine.UIElementsGameObjectsModule` to the project assemblies list