add kcp

Src/Unity/Scripts/UX/Library/TabContainer.cs

@@ -1,3 +1,4 @@
+using System;
 using System.Collections;
 using System.Collections.Generic;
 using System.Linq;
@@ -50,6 +51,7 @@ namespace BITKit.UX
 			_container.pickingMode = PickingMode.Ignore;
 		}
 		public override VisualElement contentContainer => _container;
+		public event Action<int> OnTabChanged; 
 		private int currentTab=-1;
 
 		public int CurrentTab
@@ -116,6 +118,7 @@ namespace BITKit.UX
 			}
 			if(_container.Children().TryGet(index,out var element))
 				element.SetActive(true);
+			OnTabChanged?.Invoke(index);
 		}
 	}
 }