void SetIndexForController(DetailViewController page, int index)
 {
     if (index > MaximumPageIndex)
         return;
     var e = collectionView.Entries [index];
     if (e.ResourceType == WebDavResourceType.Collection)
         return;
     page.Filename = e.Href;
 }
 int GetIndexForController(DetailViewController page)
 {
     for (int i = 0; i < collectionView.Entries.Count; ++i)
         if (collectionView.Entries [i].Href == page.Filename)
             return i;
     return -1;
 }