Filtering Layers By Geometry

AutoCAD Map 3D Geospatial Platform API

Filtering Layers By Geometry

The layer definition for a vector layer can include a <Filter> element to select only certain features. The filter is a string that contains a valid FDO selection expression. See Selecting Using the API for a description of filters.

For example, assume the following:

  • geomPoly is an MgPolygon representing the area of interest.
  • geometry is the default geometry property for a feature class.

The following creates a filter to select only those features that intersect the polygon.

MgWktReaderWriter rw = new MgWktReaderWriter();
string wktGeom = rw.Write(geomPoly);
string filter = "geometry intersects GeomFromText(" +
  wktGeom + ")" );

To modify the sample in Layer Definition to use the filter, set the <Filter> element as follows:

vectorLayerDef.Filter = filter;