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Using MapPoint 2001 from C++ - the 'FindAddress' Problem

The MFC ClassWizard makes using MapPoint from C++ almost as easy as it is from VB. This article explains the basics, and provides a plug-in replacement for the MapPoint 2001 "FindAddress" not supported by ClassWizard

The simplest way talk to MapPoint via automation from C++/MFC is using ClassWizard generated wrappers - here's a brief recap how this is done:

• create or open an MFC-based application

• open ClassWizard e.g. by pressing Ctrl-W

• press the "Add Class ..." button and select "from a type library"

• locate the type library for your version of MapPoint - look for a file with a .tlb extension in the MapPoint installation directory. For the North American version of MapPoint 2001, it is called MPNA80.TLB. Select this file and press Open.
  [NOTE: If you have MapPoint 2002, the corresponding type library is called MPNA81.TLB or MPEU81.TLB in the European version.]

• For each class of the MapPoint object model you want to use in your project (e.g. _Application, _Map, Location, Pushpin), do the following:
  • select the class
    [NOTE: If you have MapPoint 2002 installed but would like to stay compatible with MapPoint 2001 on your users machines, select the classes that have an "80" in their name]

  • rename it under "class name" - use a consistent prefix, e.g. prefix all your MapPoint objects with "Mp"

• If you want, you can also rename the .CPP and header file that will be generated.

• Make sure all classes you want included are selected.

• Press OK, then OK again.

• Make sure you initialize the COM library by adding a call to AfxOleInit() in the InitInstance method of your app.

• don't forget to #include the generated header file for the MapPoint wrapper objects in your source code - the default name e.g. for MapPoint 2001 North America is MPNA80.H

   MpApplication mpApp;

   mpApp.CreateDispatch("MapPoint.Application");

   mpApp.SetVisible(true);

   MessageBox("MapPoint should be visible now ...");

   mpApp.Quit();
   mpApp.ReleaseDispatch();

  // method 'FindAddress' not emitted because of invalid 
  // return type or parameter type

A detailed description of the problem can be found in Microsoft knowledgebase article Q158451.

The good news is that a replacement "FindAddress" can be added relatively easily - the corresponding code is shown below.

(The country codes can be determined e.g. by opening the MapPoint type library in the OLE/COM object viewer available on the VC++ Tools menu)

To provide the map wrapper object the wizard generated for you with a FindAddress method, add the code above to the corresponding implementation file (e.g. MPNA80.CPP). Make sure you adapt the object name to what you selected at creation time - if your map object wrapper is called "MaptMap" instead of "MpMap" as in my case, change the MpMap::FindAddress above accordingly. Also, add the following declaration:

LPDISPATCH MpMap::FindAddress(LPCTSTR szStreet, 
                  const CStringArray& sarAddressStrings, 
                  short nCountryCode);

   MpApplication mpApp;
   MpMap mpMap;

   mpApp.CreateDispatch("MapPoint.Application");
   mpApp.SetVisible(-1);

   mpMap = mpApp.GetActiveMap();
   
   CStringArray sarAddress;

   sarAddress.Add("Redmond");
   sarAddress.Add("WA");
   sarAddress.Add("98052");

   MpLocation mpLoc = mpMap.FindAddress(
                            "1 Microsoft Way", 
                            sarAddress, 
                            244);
   mpLoc.GoTo();

   MessageBox("Press OK to close MapPoint");

   mpLoc.ReleaseDispatch();

   mpMap.SetSaved(-1);
   mpMap.ReleaseDispatch();
   
   mpApp.Quit();
   mpApp.ReleaseDispatch();

Conclusion: With ClassWizards help, remote-controlling MapPoint and other automation servers is a breeze. Methods with variable argument lists need some extra attention, but the problem is solvable.

In MapPoint 2002, "FindAddress" is still available for compatibility reasons, but it has been replaced by the more powerful "FindAddressResults" method which can return several addresses at once, and is supported by ClassWizard.

Mapping and especially GPS-related topics are a hobby - Gilles enjoys developing solutions for Microsoft MapPoint and his favorite outdoor occupation is confluence hunting.

As always, please direct questions to the newsgroup.

	MP2Kmag Internet