Extra reference after opening a file

[David Liebtag]

I am having trouble with an unexplained extra reference to Excel. I'm
hoping someone here can explain.

Here is some pseudo-code that illustrates what my code (that is written in
C) is doing:

IDIspatch * Dispatch
IDIspatch * Workbooks
IDIspatch * File
CoCreateInstance ("Excel.Application,&IDispatch)
Workbooks = PropertyGet(IDispatch,"Workbooks")
File = Invoke(Workbooks,"Open","d:\test.xls")
Workbooks::Release
File::Release
IDispatch::Release

After my program terminates, I see in the XP Task Manager that an instance
of Excel is still running. This does not happen if I skip the Open and
related Release steps.

Can anyone explain why Excel is still running?

Thanks in advance.

David Liebtag

 

[Tom Ogilvy]

In VB, this is usually because of an unreleased reference. I don't know
anything about C and COM, but I would release in the opposite order that I
created

IDIspatch * Dispatch
IDIspatch * Workbooks
IDIspatch * File
CoCreateInstance ("Excel.Application,&IDispatch)
Workbooks = PropertyGet(IDispatch,"Workbooks")
File = Invoke(Workbooks,"Open","d:\test.xls")
File::Release
Workbooks::Release
IDispatch::Release

I have reversed the release of File and Workbook.

 

[David Liebtag]

Tom,

Thanks, but I had already tried that.

David

 

[David Liebtag]

I solved the problem. The Open method returns a Workbook object. You have
to call the Workbook's Close method before releasing it.

David Liebtag