HOWTO: Create Custom AppWizards that Generate Non-MFC Projects

• 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);
      }
   }

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. 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.
• 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; 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 current DevStudio 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.

REFERENCES

Visual C++ Books Online: Visual C++; Developer Studio Environment; Automating Tasks in Developer Studio

Visual C++ Books Online: Visual C++; Visual C++ Programmer's Guide; Beginning Your Program; Creating a Custom AppWizard; Creating Custom AppWizards; Customizing the Generated Custom AppWizard Project

Visual C++ Books Online: Visual C++; Visual C++ Programmer's Guide; Adding Program Functionality; Overviews; Compiler COM Support: Overview

Keywords          : WizardIss
Version           : WINNT:5.0
Platform          : winnt
Issue type        : kbhowto