HOWTO: Create Custom AppWizards that Generate Non-MFC Projects

ID: Q173483

The information in this article applies to:

The AppWizard, included with:
- Microsoft Visual C++, 32-bit Editions, version 5.0

SUMMARY

Visual C++ 5.0 custom AppWizards always generates an MFC-based project initially. Now the custom AppWizards can change the essential MFC project settings for the generated project through the new automation object model of Developer Studio.

MORE INFORMATION

When a custom AppWizard generates a project, it cannot simply replace the automatically created .dsp project settings file. The project settings in the .dsp file are set by internal rules that assume all generated projects are MFC projects. However, Visual C++ 5.0's new object model allows custom AppWizards to modify tool settings such that all dependencies on MFC are removed from the resulting project.

The CCustomAppWiz class in Visual C++ 5.0 now has a virtual override called CustomizeProject. CustomizeProject provides the custom wizard with an IBuildProject interface. The Configurations method of IBuildProject provides an IConfiguration interface for each build configuration in the project. IConfiguration can add and remove settings supplied to tools such as the compiler. Using these methods, a custom wizard can remove settings that add dependencies on MFC.

Sample Code

Following is an example CustomizeProject override that demonstrates the removal of MFC dependencies:


   #import "c:\Program Files\DevStudio\SharedIDE\bin\ide\devbld.pkg"

   void CNoMfcCustWizAppWiz::CustomizeProject(IBuildProject* pProject)
   {
   using namespace DSProjectSystem;

      long lNumConfigs;
      IConfigurationsPtr pConfigs;
      IBuildProjectPtr pProj;
      // Needed to convert IBuildProject to the DSProjectSystem namespace
      pProj.Attach((DSProjectSystem::IBuildProject*)pProject, true);

      pProj->get_Configurations(&pConfigs);
      pConfigs->get_Count(&lNumConfigs);
      //Get each individual configuration
      for (long j = 1 ; j < lNumConfigs+1 ; j++)
      {
         _bstr_t varTool;
         _bstr_t varSwitch;
         IConfigurationPtr pConfig;
         _variant_t varj = j;

         pConfig = pConfigs->Item(varj);

         // Remove Preprocessor def for MFC DLL specifier, _AFXDLL
         varTool   = "cl.exe";
         varSwitch = "/D \"_AFXDLL\"";
         pConfig->RemoveToolSettings(varTool, varSwitch, varj);

         varTool   = "rc.exe";
         varSwitch = "/d \"_AFXDLL\"";
         pConfig->RemoveToolSettings(varTool, varSwitch, varj);

         // OPTIONAL
         // Add Libs that MFC headers would have pulled in automatically
         // Feel free to customize this listing to your tastes
         varTool = "link.exe";
         varSwitch = "kernel32.lib user32.lib gdi32.lib winspool.lib "
                     "comdlg32.lib advapi32.lib shell32.lib ole32.lib "
                     "oleaut32.lib uuid.lib odbc32.lib odbccp32.lib";
         pConfig->AddToolSettings(varTool, varSwitch, varj);
      }
   }

Note that this code sample uses features from Visual C++ 5.0's new COM compiler support. The #import statement imports and creates definitions for all of the types in the DEVBLD.PKG type library. This allows the code to use the COM smart pointers of the form IInterfacePtr, as well as the new _bstr_t and _variant_t types. All of these new types automatically clean up used memory and release held interface pointers when they go out of scope.

Also note that a standard Custom AppWizard uses a Precompiled header file, StdAfx.h. You should place the #import statement at the end of the #include list in StdAfx.h.

NOTE: the path to DevBld.Pkg will be different if you are using Visual C++ version 6.0. Assuming that Visual C++ version 6.0 was installed to the default directory on the C: drive, the #import statement should read as follows:


   #import "C:\Program Files\Microsoft Visual Studio\Common\MsDev98\Bin\IDE\DevBld.Pkg"

NOTE: The #import line above must be on the same line in your code.

Refer to the Visual C++ documentation for more information.

Caveats

Note that there is no programmatic method available for removing the internal project setting that controls the "Microsoft Foundation Classes" setting on the General Project Settings tab. Projects that are generated by custom wizards that include the code above will still appear to "Use MFC in a Shared DLL." The only way you can change this setting is by making unsupported modifications to the .dsp project settings file. However, this setting is only used by certain DevStudio MFC user interface elements, such as Class Wizard and some MFC-based component gallery components. It should have no effect on a non-MFC project.

Even after modifying project settings using AddToolSettings and RemoveToolSettings as above, DEFAULT project settings will still remain the same in Visual C++ version 5.0. If the user of a project generated by this custom AppWizard opens up Project Settings and clicks Reset, the restored project settings will include the removed MFC references. Again, the only way to prevent this is to make unsupported changes to the generated .dsp project settings file by hand after the custom AppWizard has created the project.

Visual C++ version 6.0 provides a new automation method that changes the DEFAULT project settings. The Configuration object supports the MakeCurrentSettingsDefault method. This method changes the configuration's DEFAULT project settings to become the current settings.

When you use RemoveToolSettings, remove only one tool setting at a time. In the example above, make another call to RemoveToolSettings to remove another preprocessor definition from the CL.EXE command line rather than tacking the definition to be removed onto the end of the same varSwitch statement. Also, keep in mind that tool settings are case- sensitive, that is "/d" and "/D" are not the same thing.

Unfortunately, AddToolSettings, RemoveToolSettings, and AddCustomBuildStep (another IConfiguration method) operate on the entire project only in Visual C++ version 5.0; they cannot make tool settings or create custom build steps for a single file. For example, it is usually desirable to add a custom build step for a project's IDL file to process the file using MIDL and generate TLB and other necessary project files. The Developer Studio 97 object model does not support this. Custom build steps for single files will have to be added by hand after the custom AppWizard generates the projects.

The Visual C++ version 6.0 object model does support methods to change file settings and add custom build steps for files. See the Visual C++ version 6.0 documentation on the following methods for the Configuration object :
AddFileSettings
RemoveFileSettings
AddCustomBuildStepToFile

REFERENCES

In the Visual C++ Online Help Index:

Automating Tasks In Developer Studio

Custom AppWizards

COM Support

Keywords : kbcode kbwizard kbVC500
Version : WINNT:5.0
Platform : winnt
Issue type : kbhowto