The SpreadsheetGear API is familiar to developers with experience using Microsoft Excel(TM) VBA or COM. In many cases, the SpreadsheetGear API is close enough to the Excel API that you can record a macro in Excel to learn which properties or methods to use in SpreadsheetGear.

Major differences between SpreadsheetGear and Excel include:

• In most cases, SpreadsheetGear uses interfaces rather than classes. Use SpreadsheetGear.IWorkbook instead of Microsoft.Office.Interop.Excel.Workbook.
• SpreadsheetGear integer indexes for workbooks, worksheets, rows, columns, etc... are zero based while Excel indexes are generally one based.
• Many formatting properties (such as IRange.Font.Color) in Excel return System.Object. This is done so that null may be returned if all of the represented cells and objects do not have the same value for the particular property. Unfortunately, this bypasses type safety at compile time and causes unnecessary complexity for the vast majority of use cases. SpreadsheetGear improves on this by returning the appropriate type (such as SpreadsheetGear.Color), and providing a separate boolean property (such as IRange.Font.ColorDefined) which specifies whether all represented cells/objects have the same value for the property in question.
• Enumerations leave out XL on enumeration type names and the leading xl on enumeration identifiers. Use SpreadsheetGear.SheetType.Worksheet instead of Microsoft.Office.Interop.Excel.XLSheetType.xlWorksheet.
• Use SpreadsheetGear.IWorkbookSet in the place of Microsoft.Office.Interop.Excel.Application.
• Since the SpreadsheetGear namespace does not have any notion of a window, properties which are set via Excel's Window object must be handled differently than they are in Excel. The SpreadsheetGear.IWorkbookWindowInfo and SpreadsheetGear.IWorksheetWindowInfo interfaces provide access to these properties.
• When using the SpreadsheetGear Windows Forms, WPF and Silverlight Controls with interruptible background calculation enabled, GetLock and ReleaseLock must be used. See GetLock and ReleaseLock for more information.
• When the SpreadsheetGear Help is installed, Visual Studio's IntelliSense and Dynamic Help provide context sensitive help which simplifies development.