How to Run a Code Resource from a Visual C++ Application (136997)

SUMMARY

This article illustrates loading and executing stand-alone Code Resources from a Visual C++ application using the sample code shipped with the Visual C++ Macintosh add-on.

Chapter 8 of the 68K Programmer's Guide in the Visual C++ Books Online discusses using stand-alone code and shared libraries in 68K programs. This chapter provides a brief set of instructions on how to call a code resource. For more information on Macintosh Code Resources, please refer to this chapter in the Books Online.

MORE INFORMATION

To load a Code Resource, the Macintosh System provides a function (GetResource) that will load any resources including code resources and return a handle to a code resource. Visual C++ provides a function (_PvApplyFixup) that will take a handle to a code resource and return a pointer to the entry point. You can use these two functions to run a code resource from a Visual C++ application. The following example demonstrates how to load and execute the SACODE sample's INIT code resource.

Step-by-Step Example

Build the SACODE sample project located in Msvc20\Samples\M68k\Sacode and copy the resulting file to the Macintosh. Give the remote executable path and file name. For example:

Macintosh HD:Testing:SACODE

Make a copy of the SKEL sample located in Msvc20\Samples\M68k\Skel and call it MYSKEL. Then, make the following modifications:

Add an include for Resource.h in Skel.c. For example, after this line:

         #include <macos\QuickDra.h>

      add this line:

         #include <macos\Resource.h>

Add a prototype for _PvApplyFixup and modify the DoAbout function to look like this:

      extern ProcPtr _PvApplyFixup(Handle);

      DoAbout ()
      {
      //   SetParamText (aboutStr);
      //   (void) Alert (aboutAlrt, nil);
      //   return 0;

           Handle hResource;
           ProcPtr pCode;

           hResource = GetResource('INIT',1);   // load the resource
           if (hResource != NULL)               // make sure it's loaded
      {
           HLock(hResource);                    // lock down the handle
           pCode = _PvApplyFixup(hResource);    // get pointer to function
           pCode();                             // call the code resource
           HUnlock(hResource);
      }

      return 0;
      }

Build the MYSKEL sample project, and copy the executable to the Macintosh. Give the remote executable path and file name. For example:

Macintosh HD:Testing:MYSKEL
Use a Macintosh resource editor application such as ResEdit to copy the INIT resource in the SACODE file to the MYSKEL executable.
Execute the MYSKEL program, and click About on the Help menu. The code resource will be executed, resulting in a series of five beeps.