public ExtendedFilePropertiesPart Do(SpreadsheetDocument package, XlsxFileContent content) { var properties = new Properties(); properties.AddNamespaceDeclaration("vt", "http://schemas.openxmlformats.org/officeDocument/2006/docPropsVTypes"); properties.Append( new Application { Text = "Microsoft Excel" }, new DocumentSecurity { Text = "0" }, new ScaleCrop { Text = "false" }, new HeadingPairs( MakeVector(VectorBaseValues.Variant, new Variant(new VTLPSTR { Text = "Ћисты" }), new Variant(new VTInt32 { Text = content.Worksheets.Length.ToString() }) ) ), new TitlesOfParts( MakeVector(VectorBaseValues.Lpstr, content.Worksheets.Select(x => new VTLPSTR { Text = x.Title }) ) ), new Company { Text = content.Properties.Company }, new LinksUpToDate { Text = "false" }, new SharedDocument { Text = "false" }, new HyperlinksChanged { Text = "false" }, new ApplicationVersion { Text = "15.0300" } ); var extendedFilePropertiesPart = package.AddNewPart <ExtendedFilePropertiesPart>(); extendedFilePropertiesPart.Properties = properties; return(extendedFilePropertiesPart); }