The Office application you are automating continues to
reside in memory after your Visual C++ program finishes executing.
Most likely the application is still in memory because you
have forgotten to release an acquired interface.
Here are some general suggestions and things to looks for
when trying to determine the cause of the problem:
- If you're using #import, it is very likely you could be
running into one of the reference-counting bugs associated with it. Often these
bugs can be worked around, but usually it is preferred to use one of the other
Automation methods. #import doesn't work very well with the Office applications
because its type libraries and use are fairly complex. Also, such reference
counting problems are hard to track down because a lot of the interface-level
COM calls are behind-the-scenes when using #import.
- Check to see if you are calling any methods, such as Open
or New, that return an IDispatch * (LPDISPATCH), and ignoring the return value.
If you are, then you are abandoning this returned interface and you will need
to change your code so that you release this IDispatch * when no longer
needed.
- Gradually comment out sections of your code until the
problem disappears, then add it back judiciously to track down where the
problem starts.
- Note that some applications will stay running if the user
has "touched" the application. If this occurs while you are automating, then
the application will probably stay running afterwards. Office applications have
a "UserControl" property on the Application object that you can read/write to
change this behavior.
- Also, some applications will decide to stay running if
enough user-interface "action" has occurred. If you intend for the application
to exit, then call its Quit() method on the Application object. Word will shut
down regardless of its reference count when Quit is called. This isn't expected
COM behavior. Excel, however, will properly just hide itself but stay running
until all outstanding interfaces are released. In general, you should release
all outstanding references, and only call Quit() if you intend the application
to quit.
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