DDE link cache in DDEML library - is it so?

[anand]

Hi,

I am facing a strange error. I have a dde server running
continously at the background. Users, by establishing a
dde link on Excel, can view latest market data. The
string passed as topic and item are case sensitive in
this application.

Let me describe the problem with an example (I have changed
the original strings which we are using):

1. User types =appname|abcd!EFGH in an excel cell.
User sees N/A on cell because the topic should have
been in capital lettters.

2. So user deletes that link and types =appname|ABCD!EFGH
User should have got the value returned by dde server,
but instead sees N/A.

3. I see the server log file and find that both the times,
the server received topic with small letters. That made
me think - is Excel caching the links ? Even if I close
and open Excel and type =appname|ABCD!EFGH, I get abcd
(with small letters instead of capital) as topic in my
dde server.

4. Then I thought of stopping and starting the dde server.
This time I got the value! Does that mean that the
DDEML library is caching the link and not Excel ? So
that when i stop the DDE server, the resource associated
with that instance is flushed by DDEML library (and that
includes any cache of dde links used earlier by the user)

Can someone validate this ? How do I overcome this problem ?
Any hint/pointers will be helpful.

saha
--

 

[K Dales]

Interesting phenomenon: I know only the basics of DDE and nothing at all
about how the server processes the requests, but it does appear that it is
keeping a "history" of requests and that even though the output of the
request is case sensitive, it is not treating the "lookup" of the prior
request in a case-sensitive manner.

Don't know what to suggest, except to maybe try bypassing the DDEML library
and sending raw DDE through the API!