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TempConsumer
The TempConsumer sample
demonstrates a temporary asynchronous event consumer application. TempConsumer consumes events produced by the
provider in the EventProvider WMI SDK sample project. The events that this consumer requests are those of class MyEvent. The EventConsumer program will continue to
run and print received event information until the user presses the
<ENTER> key.
NOTE: The
TempConsumer sample registers to receive WMI events of the MyEvent class
which are generated by the EventProvider sample. If the EventProvider sample provider has not been built and
registered prior to using the TempConsumer sample, TempConsumer will not
receive any events. Refer to the
EventProvider sample documentation for instructions on building and registering
the provider.
Building the TempConsumer Application
The application can be
built from the command line using NMAKE, or it can be built using Microsoft
Visual C++.
From the command line in
the sample installation directory, type the following:
NMAKE /f "Makefile"
From Microsoft Visual
C++:
1. Select File + Open Workspace
2. Select the TempConsumer.dsp file
Using the TempConsumer
Application
TempConsumer.exe
General Notes
Things
to remember when you're building your own WMI client application:
1.
If you want your client to run
on NT and non-DCOM versions of Windows 95, manually load the ole32.dll and see
if CoInitializeSecurity() exists. This routine won’t exist on Windows 95
installations that don’t have DCOM installed separately. If this routine
doesn't exist, the asynchronous routines in this sample won’t work because of
mismatched security level problems. The synchronous techniques will still work.
2.
If you don’t care about
non-DCOM versions of Windows 95, you can define _WIN32_DCOM so that CoInitializeSecurity() is available for
implicit linking. Don't use _WIN32_WINNT to get this prototype since it won't
compile under the Windows 95/98 operating systems.
3.
In any case, the
CoInitializeSecurity() call (in InitInstance()) is required to work around a
security problem when WMI trying to call a Sink object but won't identify
itself. The CoInitializeSecurity() call turns off the authentication
requirement.
4.
WMI interfaces are defined
in wbemcli.h and wbemprov.h found in the wmi\include directory. You may #include both these files by
including just wbemidl.h located in the same directory.
5.
WMI interface CLSIDs are
defined in wbemuuid.lib. If you get unresolved externals in interfaces and
CLSIDs, this is what is missing.
6.
You'll need to link with
oleaut32.lib and ole32.lib to get the needed COM support.
7.
In the Link|Output
settings, specify 'wWinMainCRTStartup' as the entry point. This is per the
Unicode programming instructions.
8.
If you're using the makefiles, don't forget to set the Visual C++
environment variables. This is done by running VCVARS32.BAT.