Resolved (never mind) Making a list of VisualElement results in NullReferenceException

I'm trying to make list a of VisualElement(s), so i can hide some of them. When i try to hide the first one it works just fine, but when i try to add them to a list i get an exception.

My .uxml looks like this:


The code PickCardColumn.cs looks like this:

Code (CSharp):

1. using UnityEngine;
2. using UnityEngine.UIElements;
3. using System.Collections;
4. using System.Collections.Generic;
5.  
6. public class PickCardColumn : VisualElement
7. {
8.     int columns = 5;
9.     List<VisualElement> columnVEs;
10.     public new class UxmlFactory : UxmlFactory<PickCardColumn, UxmlTraits> { }
11.     public PickCardColumn()
12.     {
13.         this.RegisterCallback<GeometryChangedEvent>(OnGeometryChange);
14.     }
15.     void OnGeometryChange(GeometryChangedEvent evt)
16.     {
17.  
18.         this.Q($"ColumnPicker0").style.display = DisplayStyle.None;
19.         for (int i = 0; i < columns; i++)
20.         {
21.             Debug.Log($"ColumnPicker{i}");
22.             columnVEs[i] = this.Q($"ColumnPicker{i}");
23.         }
24.  
25.         columnVEs[1].style.display = DisplayStyle.None;
26.         this.UnregisterCallback<GeometryChangedEvent>(OnGeometryChange);
27.  
28.     }
29. }

Debug output:

Code (CSharp):

1. ColumnPicker0
2. UnityEngine.Debug:Log (object)
3. PickCardColumn:OnGeometryChange (UnityEngine.UIElements.GeometryChangedEvent) (at Assets/UI/PickCardColumn.cs:20)
4. UnityEngine.GUIUtility:ProcessEvent (int,intptr,bool&)
5.  

The exception i get is:

Code (CSharp):

1. NullReferenceException: Object reference not set to an instance of an object
2. PickCardColumn.OnGeometryChange (UnityEngine.UIElements.GeometryChangedEvent evt) (at Assets/UI/PickCardColumn.cs:21)
3. UnityEngine.UIElements.EventCallbackFunctor`1[TEventType].Invoke (UnityEngine.UIElements.EventBase evt) (at Library/PackageCache/com.unity.ui@1.0.0-preview.14/Core/Events/EventCallback.cs:64)
4. UnityEngine.UIElements.EventCallbackRegistry.InvokeCallbacks (UnityEngine.UIElements.EventBase evt) (at Library/PackageCache/com.unity.ui@1.0.0-preview.14/Core/Events/EventCallbackRegistry.cs:341)
5. UnityEngine.UIElements.CallbackEventHandler.HandleEvent (UnityEngine.UIElements.EventBase evt) (at Library/PackageCache/com.unity.ui@1.0.0-preview.14/Core/Events/EventHandler.cs:147)
6. UnityEngine.UIElements.CallbackEventHandler.HandleEventAtTargetPhase (UnityEngine.UIElements.EventBase evt) (at Library/PackageCache/com.unity.ui@1.0.0-preview.14/Core/Events/EventHandler.cs:125)
7. UnityEngine.UIElements.EventDispatchUtilities.PropagateEvent (UnityEngine.UIElements.EventBase evt) (at Library/PackageCache/com.unity.ui@1.0.0-preview.14/Core/Events/IEventDispatchingStrategy.cs:74)
8. UnityEngine.UIElements.DefaultDispatchingStrategy.DispatchEvent (UnityEngine.UIElements.EventBase evt, UnityEngine.UIElements.IPanel panel) (at Library/PackageCache/com.unity.ui@1.0.0-preview.14/Core/Events/DefaultDispatchingStrategy.cs:15)
9. UnityEngine.UIElements.EventDispatcher.ApplyDispatchingStrategies (UnityEngine.UIElements.EventBase evt, UnityEngine.UIElements.IPanel panel, System.Boolean imguiEventIsInitiallyUsed) (at Library/PackageCache/com.unity.ui@1.0.0-preview.14/Core/EventDispatcher.cs:377)
10. UnityEngine.UIElements.EventDispatcher.ProcessEvent (UnityEngine.UIElements.EventBase evt, UnityEngine.UIElements.IPanel panel) (at Library/PackageCache/com.unity.ui@1.0.0-preview.14/Core/EventDispatcher.cs:340)
11. UnityEngine.UIElements.EventDispatcher.ProcessEventQueue () (at Library/PackageCache/com.unity.ui@1.0.0-preview.14/Core/EventDispatcher.cs:302)
12. UnityEngine.UIElements.EventDispatcher.OpenGate () (at Library/PackageCache/com.unity.ui@1.0.0-preview.14/Core/EventDispatcher.cs:266)
13. UnityEngine.UIElements.EventDispatcherGate.Dispose () (at Library/PackageCache/com.unity.ui@1.0.0-preview.14/Core/EventDispatcher.cs:75)
14. UnityEngine.UIElements.UIRLayoutUpdater.Update () (at Library/PackageCache/com.unity.ui@1.0.0-preview.14/Core/Renderer/UIRLayoutUpdater.cs:56)
15. UnityEngine.UIElements.VisualTreeUpdater.UpdateVisualTreePhase (UnityEngine.UIElements.VisualTreeUpdatePhase phase) (at Library/PackageCache/com.unity.ui@1.0.0-preview.14/Core/VisualTreeUpdater.cs:155)
16. UnityEngine.UIElements.Panel.UpdateForRepaint () (at Library/PackageCache/com.unity.ui@1.0.0-preview.14/Core/Panel.cs:948)
17. UnityEngine.UIElements.Panel.Repaint (UnityEngine.Event e) (at Library/PackageCache/com.unity.ui@1.0.0-preview.14/Core/Panel.cs:991)
18. UnityEngine.UIElements.UIElementsUtility.DoDispatch (UnityEngine.UIElements.BaseVisualElementPanel panel) (at Library/PackageCache/com.unity.ui@1.0.0-preview.14/Core/UIElementsUtility.cs:446)
19. UnityEngine.UIElements.UIElementsUtility.UnityEngine.UIElements.IUIElementsUtility.ProcessEvent (System.Int32 instanceID, System.IntPtr nativeEventPtr, System.Boolean& eventHandled) (at Library/PackageCache/com.unity.ui@1.0.0-preview.14/Core/UIElementsUtility.cs:209)
20. UnityEngine.UIElements.UIEventRegistration.ProcessEvent (System.Int32 instanceID, System.IntPtr nativeEventPtr) (at Library/PackageCache/com.unity.ui@1.0.0-preview.14/Core/UIElementsUtility.cs:74)
21. UnityEngine.UIElements.UIEventRegistration+<>c.<.cctor>b__1_2 (System.Int32 i, System.IntPtr ptr) (at Library/PackageCache/com.unity.ui@1.0.0-preview.14/Core/UIElementsUtility.cs:28)
22. UnityEngine.GUIUtility.ProcessEvent (System.Int32 instanceID, System.IntPtr nativeEventPtr, System.Boolean& result) (at <6ddf8eac3856492ab1b8cf42618915cc>:0)

 

Thanks for answering, done.