AddMaterials.Command.ReadMaterialsFromXlsx C# (CSharp) Method

        private IEnumerable<MaterialViewModel> ReadMaterialsFromXlsx( 
            Dictionary<string, Material> materials,
            Dictionary<string,
            FillPatternElement> fillPatterns)
        {
            Excel.Application excel
            = new Excel.Application();

              excel.Visible = false;

              Excel.Workbook workbook = excel.Workbooks.Open(
            _input_file_name, 0, true, 5, "", "", true,
            Excel.XlPlatform.xlWindows, "\t", false,
            false, 0, true, 1, 0 );

              Excel.Worksheet worksheet = (Excel.Worksheet)
                                  workbook.Worksheets.get_Item( 1 );

              Excel.Range range = worksheet.UsedRange;

              int iRow = 5;

              while( null != range.Cells[iRow, 1].Value2 )
              {
            string matName = (string) range.Cells[iRow, 1].Value2;
            matName += " " + (string) range.Cells[iRow, 2].Value2;
            matName += " " + (string) range.Cells[iRow, 3].Value2;
            if( !string.IsNullOrEmpty( matName ) )
            {
              double red = (double) range.Cells[iRow, 4].Value2;
              double green = (double) range.Cells[iRow, 5].Value2;
              double blue = (double) range.Cells[iRow, 6].Value2;
              double transparency = (double) range.Cells[iRow, 8].Value2;
              string surPatternName = (string) range.Cells[iRow, 9].Value2;
              string cutPatternName = (string) range.Cells[iRow, 10].Value2;
              string csi = (string) range.Cells[iRow, 11].Value2;

              FillPatternElement fillPatternElement;
              FillPattern surfacePattern = null, cutPattern = null;
              if( fillPatterns.TryGetValue( surPatternName, out fillPatternElement ) )
            surfacePattern = fillPatternElement.GetFillPattern();

              if( fillPatterns.TryGetValue( cutPatternName, out fillPatternElement ) )
            cutPattern = fillPatternElement.GetFillPattern();

              var status = Status.Normal;
              if( !materials.ContainsKey( csi ) )
            status = Status.BaseMaterialClassNotFound;
              if( materials.ContainsKey( matName ) )
            status = Status.ProjectAlreadyContainsMaterialWithTheSameName;

              yield return new MaterialViewModel
              {
            Name = matName,
            BaseMaterialClass = csi,
            Color = new Color(
              Byte.Parse( red.ToString() ),
              Byte.Parse( green.ToString() ),
              Byte.Parse( blue.ToString() ) ),
            Transparency = transparency,
            SurfacePattern = surfacePattern,
            CutPattern = cutPattern,
            Status = status,
            AddToProject = status == Status.Normal
              };
            }
            ++iRow;
              }
              workbook.Close( true, null, null );
              excel.Quit();
        }