How to call a VSTO AddIn method from a separate C# project?

Question

I have a C# Excel Add-in project \"MyExcelAddIn\" that has a public method Foo() to do something complex. For testing purposes, the add-in also defines a toolbar button whic

Answer 1

For anyone else who finds this here's what I did:

        object addInName = "AddinName";
        var excelApplication = (Microsoft.Office.Interop.Excel.Application)Marshal.GetActiveObject("Excel.Application");
        COMAddIn addIn = excelApplication.COMAddIns.Item(ref addInName);

        addIn.Object.AddinMethodName(params);

Also had to add a reference to Microsoft.Office.Core under COM and Excel.Interop under Assemblies.