diff --git a/Toolkit.Foundation/ObservableCollection.cs b/Toolkit.Foundation/ObservableCollection.cs
index 763ca7c..ba218c5 100644
--- a/Toolkit.Foundation/ObservableCollection.cs
+++ b/Toolkit.Foundation/ObservableCollection.cs
@@ -144,13 +144,22 @@ public partial class ObservableCollection<TItem> :
         }
     }
 
-    public void SetSource(IList<TItem> source)
+    private Func<TItem> defaultSelectionFactory;
+
+    public void SetSource(IList<TItem> source, 
+        Func<TItem>? defaultSelectionFactory)
     {
         foreach (TItem item in source)
         {
             Add(item);
         }
 
+        if (defaultSelectionFactory is not null)
+        {
+            this.defaultSelectionFactory = defaultSelectionFactory;
+            SelectedItem = defaultSelectionFactory.Invoke();
+        }
+
         if (source is INotifyCollectionChanged observableSource)
         {
             observableSource.CollectionChanged -= SourceCollectionChanged;
@@ -193,6 +202,11 @@ public partial class ObservableCollection<TItem> :
                     {
                         Add(item);
                     }
+
+                    if (defaultSelectionFactory is not null)
+                    {
+                        SelectedItem = defaultSelectionFactory.Invoke();
+                    }
                 }
                 break;
         }
@@ -266,6 +280,8 @@ public partial class ObservableCollection<TItem> :
 
     public void Reset(Action<ObservableCollection<TItem>> factory, bool disposeItems = true)
     {
+        SelectedItem = default;
+
         Clear(disposeItems);
         factory.Invoke(this);
     }