What is Excel Add-in.
Add-in is a way to extend functionality of Microsoft Excel application. Developer can use it to add new
worksheet functions, add new features to Excel or program Excel's behavior for custom tasks.
Possible the following types of Excel Add-ins:
- Excel Add-ins written in the VBA
- COM Add-ins
- Automation Add-ins
Excel Add-in written in the VBA is represented by XLA, XLAM files. This type of add-ins is limited
by the features available in the Visual Basic for Automation. You can use password to protect
your VBA code in the XLA, XLAM file. But this protection can be easily broken. If you are professional
VBA Developer we would like to introduce you LockXLS
workbook copy protection software.
COM Add-in is an in-process COM server which implements IDTExtensibility2 interface. COM Add-ins are binary
modules which doesn't require such protection, like Add-ins written using the VBA. Functions implemented
in this type of add-in can't be used in the cells functions. You can use it to add menu command to ribbon
or menu and implement your handler.
Automation Add-in is an add-in similar to COM Add-in, but it's functions can be used in the cells formulas.