Peter - I agree that, in theory that would be causing the problem; I
just don't know what I could do differently in my code - again, here
are the code snippets:
Excel.AppEvents_SheetSelectionChangeEventHandler
EventDel_SheetSelectionChange;

OnConnection(...){
EventDel_SheetSelectionChange = new
AppEvents_SheetSelectionChangeEventHandler(API.App lication_SheetSelectionChange);
m_Excel.SheetSelectionChange += EventDel_SheetSelectionChange;
}

OnDisconnection(...){
m_Excel.SheetSelectionChange -= EventDel_SheetSelectionChange;
Marshal.ReleaseComObject(EventDel_SheetSelectionCh ange);
EventDel_SheetSelectionChange = null;
}





On Sep 17, 3:55*pm, "Peter T" <peter_t@discussions wrote:
I don't know C# but I'd look further into this bit

Removing the delegate from the event
(and releaseing the COM reference) in the OnDisconnection
method does not help.

maybe you have more than one reference that you have not released (not
necessarily the app)

Regards,
Peter T

wrote in message

...

My C# add-in implements IDTExtensibility2. *As long as I don't sync my
add-in to any Excel events, it works perfectly and the Excel instance
is removed when Excel is shut down.

However, my add-in must listen to some Excel events. I hook them up
during OnConnection, like so (using any of the Excel Workbook events
gives the same problem):
applicationObject.WorkbookOpen += new
Microsoft.Office.Interop.Excel.AppEvents_WorkbookO penEventHandler(applicationObject_WorkbookOpen);
Once I add this line of code, the Excel instance sticks around, even
after Excel is terminated and released. *Removing the delegate from
the event (and releaseing the COM reference) in the OnDisconnection
method does not help.

Using .Net 2.0 and the issue exists with at least Office XP and 2003.

The code used to test the creation and release of the Excel instance
is he
Sub Test()
* *Set oXL = CreateObject("Excel.Application")
* *Set WBs = oXL.Workbooks
* *Set Wkbk = WBs.Add
* *Set Wkbk = Nothing
* *Set WBs = Nothing
* *oXL.Quit
* *Set oXL = Nothing
End Sub