SAMPLE: Handling Callbacks with C++ Member Functions

• Microsoft Windows Software Development Kit (SDK) for Windows, version 3.1

The CALLB application demonstrates how to handle callbacks with C++ member functions. It is a companion application for the technical article on the MSDN, "Calling All Members: Member Functions as Callbacks."

Microsoft Windows version 3.1 has over 30 callback functions that applications can use to enumerate objects, hook into the hardware, and perform a variety of other activities. The article explains why normal member functions cannot be used as callback functions and gives several techniques for handling callbacks. The article and source code are targeted toward Microsoft C/C++ version 7.0, but the ideas presented apply to all C++ compilers, including those by Borland and Zortech.

CALLB contains eight makefiles that create six executables: MAKE1 creates CPROG1; MAKE2 generates a compile-time error and does not create an executable; MAKE3, MAKE4, MAKE5, and MAKE6 create CPROG3, CPROG4, CPROG5, and CPROG6, respectively; and TMAKE creates CTIMER. Please refer to "Calling All Members: Member Functions as Callbacks" for more information.

NOTE: Running CPROG1 generates a general protection (GP) fault by design.

CALLB was built and tested under Microsoft Windows version 3.1.

Download CALLB.EXE, a self-extracting file, from the Microsoft Software Library (MSL) on the following services:

• Microsoft Download Service (MSDL)

        Dial (206) 936-6735 to connect to MSDL
        Download CALLB.EXE (size: 583070 bytes) 
  

• Internet (anonymous FTP)

        ftp ftp.microsoft.com
        Change to the \SOFTLIB\MSLFILES directory
        Get CALLB.EXE (size: 583070 bytes)