void DoSearchCommand(string searchText)
 {
     if (string.IsNullOrEmpty(searchText))
     {
         SearchDocumentList.Clear();
         SearchDocumentList.AddRange(DocumentList);
     }
     else
     {
         SearchDocumentList.Clear();
         SearchDocumentList.AddRange(DocumentList.Where(x => x.nomDocument.Contains(searchText)));
     }
 }
 private void DocumentList_CollectionChanged(object sender, System.Collections.Specialized.NotifyCollectionChangedEventArgs e)
 {
     SearchDocumentList.Clear();
     SearchDocumentList.AddRange(DocumentList);
 }