BuildingCoder.CmdPurgeLineStyles.PurgeGraphicStyles C# (CSharp) Method

        void PurgeGraphicStyles( 
            Document doc,
            string name_substring)
        {
            FilteredElementCollector graphic_styles
            = new FilteredElementCollector( doc )
              .OfClass( typeof( GraphicsStyle ) );

              int n1 = graphic_styles.Count<Element>();

              IEnumerable<Element> red_line_styles
            = graphic_styles.Where<Element>( e
              => e.Name.Contains( name_substring ) );

              int n2 = red_line_styles.Count<Element>();

              if( 0 < n2 )
              {
            using( Transaction tx = new Transaction( doc ) )
            {
              tx.Start( "Delete Line Styles" );

              doc.Delete( red_line_styles
            .Select<Element, ElementId>( e => e.Id )
            .ToArray<ElementId>() );

              tx.Commit();

              TaskDialog.Show( "Purge line styles",
            string.Format(
              "Deleted {0} graphic style{1} named '*{2}*' "
              + "from {3} total graohic styles.",
              n2, ( 1 == n2 ? "" : "s" ),
              name_substring, n1 ) );
            }
              }
        }