Tidied up docs and fixed several methods to be virtual

docfx/articles/treeview.md

@@ -35,35 +35,24 @@ Having to create a bunch of TreeNode objects can be a pain especially if you alr
 ```csharp
 // Your data class
 private class House : TreeNode {
-
-
+		
     // Your properties
     public string Address {get;set;}
     public List<Room> Rooms {get;set;}
 
     // ITreeNode member:
+	public override IList<ITreeNode> Children => Rooms.Cast<ITreeNode>().ToList();
 
-    public IList<ITreeNode> Children => Rooms.Cast<ITreeNode>().ToList();
-    
-    public override string ToString ()
-    {
-        return Address;
-    }
+	public override string Text { get => Address; set => Address = value; }
 }
 
+
 // Your other data class
 private class Room : TreeNode{
-    
+           
     public string Name {get;set;}
 
-
-    // Rooms have no sub objects
-    public IList<ITreeNode> Children => new List<ITreeNode>();
-
-    public override string ToString ()
-    {
-        return Name;
-    }
+	public override string Text{get=>Name;set{Name=value;}}
 }
 ```