I think I found an answer, although not a solution. It seems that the
problem is in the data quality of the different map provider that are
used for Google Maps and MapView in SDK, which differ.
The map tiles coordinates don't seem to be very accurate, just like in
the public google maps web api / tiles.
See this screenshot for an example, where I pinned the same geo point.
http://img339.imageshack.us/i/gmaps2.png/
The map using the public map api is off a few hundred meters.
Seems that we just have to live with it.
On Jul 20, 6:32 pm, Mathias Lin <m...@mathiaslin.com> wrote:
> I have a mapview where I want to track the user's current location. GPS
> as well as 'use wireless networks' is activated in my phone settings.
> Nevertheless, since I'm indoor I don't get a GPS fix, therefore the
> location is determined via network; wifi spot is available.
>
> I have the Google Maps app running as well as my application running.
>
> Strangely, the current location differes between Google Maps and my
> application, where the Google Maps is very accurate while in my app the
> location is somehow off a few 100 meters.
>
> In my application I basically do the following (for debugging
purposes now):
>
> 1) initially place one marker on the map: geopoint retrieved via
> locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
>
> 2) initially place another marker on the map: geopoint retrieved via
> locationManager.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
>
> This will put the last known locations of both providers onto the map
> (eventually last known from outside my app).
>
> 3) then for the regular updates (since I don't get a GPS fix anyway
> indoor here), I do:
> locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER,
> 0, 0, baseLocationListener);
>
> You can see for the frequency and distance I pass the 0 param in both
cases.
>
> In the app manifest, the following permissions are granted:
> android.permission.ACCESS_COARSE_LOCATION
> android.permission.ACCESS_FINE_LOCATION
> android.permission.ACCESS_MOCK_LOCATION
>
> Actually my baseLocationListener does get called, which I see in the
> log, but the updated location is somehow the same as the last known
> current position (of LocationManager.NETWORK_PROVIDER), same lat/lng.
>
> I thought maybe I overlooked something or missed a parameter or setting,
> or my code has a bug. Therefore I installed some other (3 in total) LBS
> apps from the Android market that also show the current user's location.
> The current locations displayed in those apps are equals to the one in
> my application - and they're all some 100 meters off - but at least all
> the same.
>
> See the screenshot
here:http://img33.imageshack.us/img33/8679/mapproblem.png
>
> Now I am wondering:
>
> 1) as I understand, getLastKnowLocation is system-wide and not app-wide,
> why are there differences between the location in Google maps and all
> the other apps?
>
> 2) does Google Maps not update the lastKnownLocation of a provider?
>
> 3) does Google Maps use a different custom location provider (i.e. due
> to licensing reasons) other than GPS_PROVIDER or NETWORK_PROVIDER as
> they are in the SDK?
>
> 4) how do achieve the same accurate result with the NETWORK_PROVIDER
> like Google Maps does?
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