public void DidChangeValue(RenameDialog dialog, string value) { if (controllerDelegate != null) { int selectedIndex = controllerDelegate.GetIndexOfSelectedItem(this); string originalValue = controllerDelegate.GetTitleForItemAtIndex(this, selectedIndex); if (!controllerDelegate.IsNameAvailable(this, value) && value != originalValue) { dialog.ShowErrorMessage("This name is already used."); } else { dialog.ResetErrors(); } } }