Bug Inspector assignments get reset in custom controls

When working with custom controls in UI Builder, I am able to use the inspector to change assignments for properties defined as part of UxmlTraits (color and label in case of my example below). Whenever I change such an assignment, the change is visually propagated, both in current viewport and the inspector. However, when I change focus to a different element and then back, the setting in viewport persists, whereas the assignment in inspector resets to an empty value (empty string/#000000).

Any idea as to what might be causing this?

Code (CSharp):

1. using UnityEngine;
2. using UnityEngine.Scripting;
3. using UnityEngine.UIElements;
4.  
5. namespace UI
6. {
7.     public class TagLabel : VisualElement
8.     {
9.         public Label Label;
10.  
11.         public TagLabel()
12.         {
13.             Label = new Label();
14.             Add(Label);
15.         }
16.  
17.         #region UXML
18.         [Preserve]
19.         public new class UxmlFactory : UxmlFactory<TagLabel, UxmlTraits> { }
20.  
21.         [Preserve]
22.         public new class UxmlTraits : VisualElement.UxmlTraits
23.         {
24.             UxmlStringAttributeDescription m_Label = new UxmlStringAttributeDescription { name = "label", defaultValue = "Label" };
25.             UxmlColorAttributeDescription m_Color = new UxmlColorAttributeDescription { name = "color", defaultValue = Color.gray };
26.  
27.             public override void Init(VisualElement ve, IUxmlAttributes bag, CreationContext cc)
28.             {
29.                 base.Init(ve, bag, cc);
30.                 var instance = ve as TagLabel;
31.  
32.                 instance.Clear();
33.                 instance.label = m_Label.GetValueFromBag(bag, cc);
34.                 instance.color = m_Color.GetValueFromBag(bag, cc);
35.  
36.                 instance.style.backgroundColor = instance.color;
37.                 instance.Add(new Label("Label") { text = instance.label });
38.  
39.                 instance.ClearClassList();
40.                 instance.AddToClassList("tag");
41.             }
42.         }
43.         #endregion
44.  
45.         public string label;
46.         public Color color;
47.     }
48. }

 

try adding get set to your color property

Code (CSharp):

1. public Color color {get; set;}

 

Yup, that works. Thanks!