private void delete(int?index)
 {
     if (index < CameraNameList.Count)
     {
         CameraNameList.RemoveAt(SelectedIndex);
     }
 }
        private void add(ObservableCollection <CameraNameWrapper> list)
        {
            CameraNameWrapper item = new CameraNameWrapper(null);

            item.NotAssociated = true;
            CameraNameList.Add(item);
        }