I too have the same problem. I need to have a C# program determine in which US State contains a specific location specified in latitude,longitude. Can this be determined from the results supplied by GetLocation?

This is my very first attempt to use MapPoint from a program, so I'm a total newbie. I have MP2006 however, not MP2004.

Hi,

This can easy be done, this is example:

Code:

    Location loc = MP.ActiveMap.GetLocation(lat, lon, alt);
    FindResults StreetResults = MP.ActiveMap.ObjectsFromPoint(MP.ActiveMap.LocationToX(loc), MP.ActiveMap.LocationToY(loc));
    foreach (object o in StreetResults) {
	loc = o as Location;
	if (loc != null && loc.StreetAddress != null)
	    Console.WriteLine("country: " + loc.StreetAddress.Country);
    }

Thank you, Wilfried. I will try this ASAP. Actually it is the region name (State, for US) I am seeking, not the country name, but I will pursue this approach. Ideally, it would be great to be able to request a specific Location Type, eg. geoShowByRegion1 to get the US State name.

Would this work if the lat,long. is not near any street? I will be performing these calls using computed lat,long coordinates as part of a search to find the nearest region (State) boundary along a given path, by stepping along the path until the State name changes. (Unless there is an easier way to locate the distance to the border in a given direction.)

Hi,

There is a Region property too. So if a US State is the same as a Region (in my language a State is not a region but more like a Country) then you probably can yous that property. Please feedback about this

As for you other question you go high altitude. 10 Miles or so even a little higher then you will have always StreetAddresses (with a larger delusion of precision) (you should always check for null value, if it is null ho higher).

Alas, I could not get this solution to work. I set MP.Units = 0 (miles) and called GetLocation(33, -118, 10) to obtain a point over Los Angeles, CA. None of the objects returned by FindResults had a nonempty Region value. It found a couple of highways (I-5 and US-395) and an object with Name = North America. It also returned an object with Name "San Diego", but its StreetAdress was null. I tried a lower altitude (1 mi), but that did not help.

Any suggestions?

Hi,

and when StreetAddress is not null, then still both Region and Country are null ?

When StreeetAddress was not null, the Region property contained an empty string. I did not check the Country property. I'll do so when I get to work.

I found the problem. The approach does work. It turns out that my choice of coordinates was wrong. I rounded the coordinates of Los Angeles incorrectly. 33N,118W is in fact over the ocean! MP was unable to find any useful objects. When I used 34N,118W and confirmed by loc.Goto() this was in fact over the city, the algorithm worked perfectly.

I also checked to see what it returned when the loc was not in a city. I tried 34N,110W and saw this was over the desert in Arizona. Although MP found no location object with a nonnull StreetAddress, it did return a Location of Type geoShowByRegion1, whose Name property was "Arizona". It would seem I can alternatively determine the State by looking for a geoShowByRegion1 Location with a valid US State name.

I will now investigate the possibility of finding a more efficient means of locating the State boundary crossings along a great circle route, which is the actual problem at hand. At least it seems this iterative solution will work if I choose test locations along the route.

Thank you very much for your help with this!

Hi,

Thank you for feedback. To check out I did some experiments, and it seems that the Location objects in the collection are included geoShowByRegion1, geoShowByRegion2, geoShowByCountry, geoShowByDefault ever, if I'm on a street, city, or not.

So I think in your case it is enough to check the type on geoShowByRegion1 and check the Name property.

Hi,

Maybe this thread is also interesting for you:
MapPoint Functionality