Loading XLL in Excel: any difference between Tools->AddIn and File->Open?

Question

I have got an XLL, and want to load it in Excel.

Is there any difference between loading using Tools->AddIn or File->Open other than

• it is impossible to unload it if I use File->Open;
• it won't be loaded automatically if I restart Excel.

Thanks!

Answer 1

Assuming you are writing an xll and not a VBA add-in, see the full story at http://xllblog.wordpress.com/2013/07/10/add-in-manager/.

Long story short, File>Open... only calls xlAutoOpen. The Add-in Manager calls xlAutoAdd then xlAutoOpen when you add the file, and xlAutoRemove then xlAutoClose when you remove the file.

Answer 2

Tools->Addin fires an additional event AddinInstall the first time the addin is installed. Personally I never use this event.
If you want to load an XLL using VBA then you have to use RegisterXLL