Assets/Scripts/Studio/UI/TreeView/CustomScrollRect.cs

@@ -24,6 +24,11 @@ namespace XED.Hierarchy
         private Coroutine coroutinePendPopup;
         public override void OnBeginDrag(PointerEventData eventData)
         {
+            ScrollItemUI itemUI = GetTargetItemUI(eventData);
+            if (itemUI != null && !itemUI.isSelected)
+            {
+                itemUI.OnPointerClick(eventData);
+            }             
             onDragBegin?.Invoke(sourceItem);
             if (!passDragToChildren)
             {

Assets/Scripts/Studio/UI/TreeView/ScrollItemUI.cs

@@ -33,6 +33,7 @@ namespace XED.Hierarchy
         public GameObject highLight;
         public List<HierarchyItemSprite> itemSprites;
         private Image backgroundImage;
+        public bool isSelected;
         private void Awake()
         {
             backgroundImage = GetComponent<Image>();
@@ -69,7 +70,8 @@ namespace XED.Hierarchy
         }
         public void SetSelected(bool selected)
         {
-            if (selected)
+            isSelected = selected;
+            if (isSelected)
             {
                 backgroundImage.color = selectedColor;
             }
@@ -80,7 +82,8 @@ namespace XED.Hierarchy
         }
         public void SetSelected(List<HierarchyItem> selectedItems)
         {
-              if (selectedItems.Contains(currentItem))
+            isSelected = selectedItems.Contains(currentItem);
+            if (isSelected)
             {
                 backgroundImage.color = selectedColor;
             }