Microsoft Office Add-ins using NetOffice

You can use the NetOffice library to create .NET Framework applications that extend Office. These applications are also named in old MSDN documentation as Office solutions or COM Add-ins for Microsoft Office.

The create Office application add-in, create a class which extends from the COMAddin class provided by the NetOffice library.

public class ExcelAddin : NetOffice.ExcelApi.Tools.COMAddin


You project can have multiple add-ins targeting different Microsoft Office applications. Each add-in class must have its unique ProgId and Guid values so it can be properly identified in COM infrastructure.

COMAddin Classes

NetOffice provides COMAddin classes for each Microsoft Office application. You will find the COMAddin class in the Tools namespace in each NetOffice library for an Office application.

Office Application NetOffice Library COMAddin Class
MS Word WordApi.dll NetOffice.WordApi.Tools.COMAddin
MS Excel ExcelApi.dll NetOffice.ExcelApi.Tools.COMAddin
MS PowerPoint PowerPointApi.dll NetOffice.PowerPointApi.Tools.COMAddin
MS Outlook OutlookApi.dll NetOffice.OutlookApi.Tools.COMAddin