The spatial reference of the map.
[Visual Basic .NET] Public Property SpatialReference As ISpatialReference
[C#] public ISpatialReference SpatialReference {get; set;}
[C++]
HRESULT get_SpatialReference(
ISpatialReference** spatialRef
);
[C++]
HRESULT putref_SpatialReference(
ISpatialReference* spatialRef
);
[C++]Parameters
spatialRef [out, retval]spatialRef is a parameter of type ISpatialReference
spatialRef [in]spatialRef is a parameter of type ISpatialReference
Product Availability
Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server.
Remarks
When the SpatialReference property is set,
the Map's MapUnits and
DistanceUnits properties are set and the
extent of the screen display is recalculated.
AddLayer automatically attempts to set the
Map's SpatialReference property if a coordinate system has not yet
been defined for the map. When multiple layers are added
simultaneously, AddLayer uses the first spatial reference it
finds.
If no layers have a spatial reference, AddLayer checks the
extent of the first layer (ILayer::AreaOfInterest) and if it has
coordinates that look like geographic coordinates (XMin >=
-180 and XMax <= 180 and YMin >= -90 and YMax <= 90),
ArcMap assumes the data is in decimal degrees and sets the MapUnits
to esriDecimalDegrees and DistanceUnits to
esriMiles.
If no spatial reference is found and the
coordinates do not look like geographic coordinates, ArcMap
sets no spatial reference and sets the MapUnits to
esriMeters and the DistanceUnits to esriMeters as
well.