ID Number: Q74278
3.00
WINDOWS
Summary:
SYMPTOMS
Spy sometimes reports messages as having been sent twice. Messages
from DDE conversations, especially the WM_DDE_DATA, WM_DDE_ACK, and
WM_DDE_POKE messages, are the most often duplicated. This behavior
can be seen by choosing All Windows from Spy's Windows menu,
selecting DDE messages in Spy's Options dialog, and then running
two applications that communicate using DDE.
CAUSE
Spy displays a message each time it is retrieved. If an application
retrieves a message once by calling PeekMessage() with PM_NOREMOVE,
and then again with GetMessage(), Spy will report it twice. Spy
cannot determine that the message was already retrieved by the
application. Since the application is using the message twice, the
message should indeed be shown twice. This is a useful feature for
determining how an application is handling the DDE messages sent to
it.