Microsoft Excel Open XML Spreadsheet (.xlsx) is a well-known format for Microsoft Excel documents that was introduced by Microsoft with the release of Microsoft Office 2007.
Learn more about this file format here
GroupDocs.Viewer (in GroupDocs.Viewer.dll) Version: 22.9
public static readonly FileType XLSX
Public Shared ReadOnly XLSX As FileType
static initonly FileType^ XLSX
static val XLSX: FileType