Maps and Layers

GISDK supports map layers from several different sources: standard geographic files, compact geographic files, external geographic file types, and images of several types. Use the following GISDK functions to add or remove map layers:

GISDK Function	Summary
AddExistingLayer()	Adds an existing layer in the workspace to a map
AddImageLayer()	Adds an image layer to a map
AddLayer()	Adds a layer from a geographic file to a map
AddLayerToWorkspace()	Adds a layer to a workspace without it appearing in a map or dataview
AddMITABLayer()	Adds a layer from a MapInfo TAB file to a map
AddODBCLayer()	Adds an ODBC layer to a map
AddSDOLayer()	Adds a layer from a Oracle Spatial table to a map
AddShapeLayer()	Adds a layer from a Esri (ArcView) Shapefile to a map
DropLayer()	Removes a layer from a map
DropLayerFromWorkspace()	Removes a layer from an application
GetLayers()	Gets information on layers in the system and the current layer.
GetMapLayers()	Gets a list of the layers in a map

AddCDFLayer() has been superceded by AddLayer().

Geographic files can contain more than one layer of information. In particular, geographic files that containing line features almost always contain an endpoint layer as well. Standard format geographic files from earlier DOS versions of Caliper Corporation's GIS products may also contain multiple layers. Use GetDBLayers() to get a list of the layers in a geographic file.

You can also have layers that appear in a GISDK application, but do not appear in any maps. This is useful if you want to retrieve geographic information from a layer without displaying it, or if you want to display the tabular data for a layer in an editor. To have a layer in an application but not in a map, use the following GISDK functions:

GISDK Function	Summary
AddLayerToWorkspace()	Adds a layer to an application without it appearing in a map or dataview
AddMITABLayerToWorkspace()	Adds a MapInfo TAB file layer to an application without it appearing in a map or dataview
AddODBCLayerToWorkspace()	Adds an ODBC layer to an application without it appearing in a map or dataview
AddSDOLayerToWorkspace()	Adds an Oracle Spatial layer to an application without it appearing in a map or dataview
AddShapeLayerToWorkspace()	Adds an Esri (ArcView) Shapefile layer to an application without it appearing in a map or dataview
DropLayerFromWorkspace()	Removes a layer from an application

For more information, see:

Layers in a GISDK Application

The GISDK Current Layer

Image Layers