| public CreateFromWkt ( string WKT ) : ICoordinateSystem | ||
| WKT | string | The Well-known text representation for the spatial reference |
| Результат | ICoordinateSystem | |
private static ICoordinateSystem GetCoordinateSystemForSrid(int srid)
{
if (srid <= 0)
{
return(null);
}
ICoordinateSystem res = null;
#if !DotSpatialProjections
if (_sridCoordinateSystem.TryGetValue(srid, out res))
{
return(res);
}
var wkt = Converters.WellKnownText.SpatialReference.SridToWkt(srid);
if (string.IsNullOrEmpty(wkt))
{
Logger.Error(fmh => fmh("No definition for SRID {0}!", srid));
return(null);
}
var csFactory = new CoordinateSystemFactory();
try
{
res = csFactory.CreateFromWkt(wkt);
}
catch (Exception)
{
Logger.Error(fmh => fmh("Could not parse definition for SRID {0}:\n{1}", srid, wkt));
return(null);
}
_sridCoordinateSystem.Add(srid, res);
#else
try
{
if (_sridDefinition != null)
{
string proj4;
if (_sridDefinition.TryGetValue(srid, out proj4))
{
res = ICoordinateSystem.FromProj4String(proj4);
}
}
if (res == null)
{
res = DotSpatial.Projections.ProjectionInfo.FromEpsgCode(srid);
}
}
catch (Exception)
{
Logger.Error(fmh => fmh("Could not get coordinate system for SRID {0}!", srid));
return(null);
}
#endif
return(res);
}
/// <summary>
/// Method to create a coordinate system based on the <paramref name="wellKnownText"/> coordinate system definition.
/// </summary>
/// <param name="wellKnownText"></param>
/// <returns>A coordinate system, <value>null</value> if no coordinate system could be created.</returns>
public CoordinateSystem CreateCoordinateSystem(string wellKnownText)
{
try
{
return(_coordinateSystemFactory.CreateFromWkt(wellKnownText.Replace("ELLIPSOID", "SPHEROID")));
}
catch (Exception)
{
// as a fallback we ignore projections not supported
return(null);
}
}
// gets transform between raster's native projection and the map projection
private void GetTransform(CoordinateSystems.ICoordinateSystem mapProjection)
{
if (mapProjection == null || _projection == "")
{
_transform = null;
return;
}
CoordinateSystemFactory cFac = new CoordinateSystemFactory();
// get our two projections
ICoordinateSystem srcCoord = cFac.CreateFromWkt(_projection);
ICoordinateSystem tgtCoord = mapProjection;
// raster and map are in same projection, no need to transform
if (srcCoord.WKT == tgtCoord.WKT)
{
_transform = null;
return;
}
// create transform
_transform = new CoordinateTransformationFactory().CreateFromCoordinateSystems(srcCoord, tgtCoord);
}
// get raster projection
public ICoordinateSystem GetProjection()
{
CoordinateSystemFactory cFac = new CoordinateSystemFactory();
try
{
if (_projection != "")
return cFac.CreateFromWkt(_projection);
}
catch { }
return null;
}