Get a MS GeoId from a 3 lettor ISO code (ISO 3166-1 alpha-3)

Question

I have a 3 letter ISO code (e.g. DEU for germany, USA for America...) and would like to get the GeoID as listed in this table, also available here How can I do that using either straight .NET, P/Invoking or through the MapPoint PIA.

e.g. given "SWE", I would like to retrieve 221.

System.Globalisation.RegionInfo looks kinda promising - but it expects 2 letter codes (US instead of USA). To that end, a 3 letter -> 2 letter conversion would also work.

Answer 1

After dicking around with Enum.* and the reflection API, I finally solved this by enumerating all possible RegionInfo's. This was possible by getting all the CultureInfos and creating RegionInfos from them.

The following code is icky and needs to be polished.

    internal MapPoint.GeoCountry GetGeocode(string isoCountryCode)
    {
        CultureInfo[] cultures = CultureInfo.GetCultures(CultureTypes.AllCultures);
        RegionInfo region = null;
        foreach (CultureInfo culture in cultures)
        {
            try
            {
                 region = new RegionInfo(culture.Name);
                 if (String.Compare(region.ThreeLetterISORegionName, isoCountryCode, true) == 0)
                     return (GeoCountry)region.GeoId;
            }
            catch
            {
            }
        }

        return GeoCountry.geoCountryDefault;
    }

Feel free to go nuts making it generic, pretty, optimised etc :)

Answer 2

Enumerate all GSIDs with EnumSystemGeoID, then use the GetGeoInfo with GEO_ISO3 as GeoType.

Of course, it is best if you do that once, cache the results, then you can map both ways, as you want.

Links:

• EnumSystemGeoID: http://msdn.microsoft.com/en-us/library/dd317826(VS.85).aspx
• GetGeoInfo: http://msdn.microsoft.com/en-us/library/dd318099(VS.85).aspx