FIX: TypeLibs with Large Argument Lists May Crash ClassWizard

The information in this article applies to:

• The ClassWizard included with: - Microsoft Visual C++, 32-bit Edition, version 4.0

SYMPTOMS

The Developer Studio crashes or abruptly terminates when attempting to add a new class from an OLE TypeLib with the ClassWizard.

CAUSE

ClassWizard allocates a 1024 byte buffer to store member function prototypes based on the information it finds in the specified OLE TypeLib. If the ClassWizard-generated prototype for a member function exceeds this limit, Developer Studio will crash or abruptly terminate.

This problem only occurs when attempting to create a new class from an OLE TypeLib, where one or more of the automation methods contains a large argument list. For example, both Microsoft Schedule+ 7.0 and Microsoft Project 4.0 expose automation methods with large argument lists. Attempting to create a new class from either the Schedule+ type library (SP7EN32.OLB) or the Microsoft Project type library (PJ4EN32.OLB) may cause Developer Studio to crash.

When the crash occurs, you will notice that a header (.H) file and an implementation (.CPP) file were added to your project's directory. These files will most likely be corrupted and should be deleted from your project directory.

RESOLUTION

Avoid using the ClassWizard to generate new classes with the previously listed type libraries. Microsoft has provided a self-extracting file, called TLBWRAP.EXE, that contains the COleDispatchDriver-derived classes that wrap the automation objects exposed by the SP7EN32.OLB and PJ4EN32.OLB type libraries.

The following file is available for download from the Microsoft Software Library:

 ~ Tlbwrap.exe

   ARTICLE-ID: Q119591
   TITLE     : How to Obtain Microsoft Support Files from Online Services

STATUS

Microsoft has confirmed this to be a bug in the Microsoft products listed at the beginning of this article. This bug was corrected in Visual C++ 4.1.