[]
Gets the file format setting for these open options.
This value identifies the workbook format associated with the current options instance, such as Csv for CsvOpenOptions or Sjs for SjsOpenOptions.
public OpenFileFormat FileFormat { get; protected set; }
Public Property FileFormat As OpenFileFormat
CsvOpenOptions options = new CsvOpenOptions();
OpenFileFormat fileFormat = options.FileFormat;
workbook.Open("path/to/data.csv", options);