public static GeoEnvelope ReadGeoEnvelopeByRegionKey(string iso3166_2RegionCode)
{
iso3166_2RegionCode = ConvertRegionCodeToIso3166_2RegionCode(iso3166_2RegionCode);
String sql = "SELECT geom FROM level1 WHERE HASC_1 = " + "'" + iso3166_2RegionCode + "'";
Layer resultLayer = _dataSource.ExecuteSQL(sql, null, "");
if (resultLayer == null)
{
return(null);
}
if (resultLayer.GetFeatureCount(0) == 0)
{
return(null);
}
Envelope envelope = new Envelope();
int ret = resultLayer.GetExtent(envelope, 1);
GeoEnvelope geoEnvelope = new GeoEnvelope();
geoEnvelope.SetData(envelope);
return(geoEnvelope);
}
static void TestCountryEnvelopeAPI()
{
string countryCode = "NGA";
GeoEnvelope NigeriaEnvelope = GeoAPI.ReadGeoEnvelopeByCountryKey(countryCode);
if (NigeriaEnvelope == null)
{
Console.WriteLine("failed to get country data for specified country code: {0}", countryCode);
return;
}
// access lat long data
List <LonLat> NigeriaEnvelopeLatLonArray = NigeriaEnvelope.GetData();
for (int i = 0; i < NigeriaEnvelopeLatLonArray.Count; i++)
{
LonLat lonlat = NigeriaEnvelopeLatLonArray[i];
Console.WriteLine("{0} th x = {1}, y = {2}", i, lonlat.longitude, lonlat.latitude);
}
// how to test result
// we can save result to geojson file, open it in GIS tool(for example QGIS) and view it.
bool saveSuccess = NigeriaEnvelope.saveToGeoJson("E:/Nigeria_Envelope.geojson");
if (!saveSuccess)
{
Console.WriteLine("failed to save Nigeria_Envelope.geojson");
}
}
public static GeoEnvelope ReadGeoEnvelopeByCountryKey(string iso3166_1CountryCode)
{
String sql = "SELECT geom FROM level0 WHERE GID_0 = " + "'" + iso3166_1CountryCode + "'";
Layer resultLayer = _dataSource.ExecuteSQL(sql, null, "");
if (resultLayer == null)
{
return(null);
}
if (resultLayer.GetFeatureCount(0) == 0)
{
return(null);
}
Envelope envelope = new Envelope();
int ret = resultLayer.GetExtent(envelope, 1);
GeoEnvelope geoEnvelope = new GeoEnvelope();
geoEnvelope.SetData(envelope);
return(geoEnvelope);
}