diff --git a/DarkUI/Collections/ObservableList.cs b/DarkUI/Collections/ObservableList.cs
index 26d683b..0cfb05a 100644
--- a/DarkUI/Collections/ObservableList.cs
+++ b/DarkUI/Collections/ObservableList.cs
@@ -80,6 +80,15 @@ protected virtual void Dispose(bool disposing)
                 ItemsRemoved(this, new ObservableListModified<T>(new List<T> { item }));
         }
 
+        public new void Clear()
+        {
+            ObservableListModified<T> removed = new ObservableListModified<T>(this.ToList<T>());
+            base.Clear();
+            
+            if (removed.Items.Count() > 0 && ItemsRemoved != null)
+                ItemsRemoved(this, removed);
+        }
+
         #endregion
     }
 }
diff --git a/DarkUI/Controls/DarkDropdownList.cs b/DarkUI/Controls/DarkDropdownList.cs
index ad43722..d9158dc 100644
--- a/DarkUI/Controls/DarkDropdownList.cs
+++ b/DarkUI/Controls/DarkDropdownList.cs
@@ -257,6 +257,12 @@ private void Items_CollectionChanged(object sender, NotifyCollectionChangedEvent
                 }
             }
 
+            if (e.Action == NotifyCollectionChangedAction.Reset)
+            {
+                _menu.Items.Clear();
+                SelectedItem = null;
+            }
+
             ResizeMenu();
         }
 
diff --git a/DarkUI/Controls/DarkTreeView.cs b/DarkUI/Controls/DarkTreeView.cs
index 2d748bd..bfecb86 100644
--- a/DarkUI/Controls/DarkTreeView.cs
+++ b/DarkUI/Controls/DarkTreeView.cs
@@ -566,6 +566,8 @@ private void UpdateNodes()
             if (IsDragging)
                 return;
 
+            ContentSize = new Size(0, 0);
+
             if (Nodes.Count == 0)
                 return;
 
@@ -573,9 +575,7 @@ private void UpdateNodes()
             var isOdd = false;
             var index = 0;
             DarkTreeNode prevNode = null;
-
-            ContentSize = new Size(0, 0);
-
+            
             for (var i = 0; i <= Nodes.Count - 1; i++)
             {
                 var node = Nodes[i];