Article: Q171457
Product(s): Microsoft C Compiler
Version(s): WINDOWS:4.2
Operating System(s):
Keyword(s): kberrmsg kbole kbActiveX kbCOMt kbEEdition kbMFC kbVC kbVC420bug kbVC500fix kbGrpDSMFCA
Last Modified: 19-JUL-2001
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The information in this article applies to:
- Microsoft Visual C++, 32-bit Enterprise Edition, version 4.2, on platform(s):
- the hardware: Intel x86
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SYMPTOMS
========
When you execute the SENDTIME sample build with Visual C++ 4.2 Enterprise
Edition without the Visual C++ 4.2b patch installed, it will fail in
CoCreateInstanceEx(). If the Visual C++ 4.2b patch is installed, the sample will
not build at all and will generate 7 compiler errors.
CAUSE
=====
Some of the structures used by DCOM have changed since the Visual C++ 4.2
Enterprise Edition shipped. As a result, the sample will fail in
CoCreateInstanceEx() with "error invalid parameter" without the Visual C++ 4.2b
patch applied. If the Visual C++ 4.2b patch is applied, the header files are
updated to reflect the correct DCOM structures. However, since the SENDTIME
source is trying to use the old structures, compilation errors will be
generated.
RESOLUTION
==========
Apply the Visual C++ 4.2b patch to update the DCOM structures in the header
files. When you build the sample, seven compiler errors will be generated. In
the project settings add the _WIN32_DCOM preprocessor symbol. Then, in the
CallMachine() function in SENDTDLG.CPP, replace the following lines:
ServerInfo.dwSize = sizeof(COSERVERINFO);
ServerInfo.pszName = T2OLE(lpszMachine);
with
memset(&ServerInfo, 0, sizeof(ServerInfo));
ServerInfo.pwszName = T2OLE(lpszMachine);
STATUS
======
Microsoft has confirmed this to be a bug in the Microsoft products listed at the
beginning of this article. This bug was fixed in Visual C++ 5.0 and later
versions.
MORE INFORMATION
================
Following are the compilation errors that are generated when you build the
sample after applying the patch:
C2039: 'dwSize' : is not a member of '_COSERVERINFO'
C2039: 'pszName' : is not a member of '_COSERVERINFO'
C2065: 'CoCreateInstanceEx' : undeclared identifier
C2064: term does not evaluate to a function SendTime.cpp
C2065: 'CoInitializeEx' : undeclared identifier
C2065: 'COINIT_MULTITHREADED' : undeclared identifier
C2064: term does not evaluate to a function
The first 2 errors are a result of the structure changing and, therefore, these
members are no longer valid. The remaining errors occur because the function
prototypes for CoCreateInstanceEx() and CoInitializeEx() are conditionally
included depending on whether the preprocessor symbol _WIN32_DCOM is defined.
Additional query words:
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Keywords : kberrmsg kbole kbActiveX kbCOMt kbEEdition kbMFC kbVC kbVC420bug kbVC500fix kbGrpDSMFCATL
Technology : kbVCsearch kbAudDeveloper kbVC32bitSearch
Version : WINDOWS:4.2
Issue type : kbbug
Solution Type : kbfix
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