ILayerDescription Interface

Provides access to the available properties of a layer description object. Note: the ILayerDescription interface has been superseded byILayerDescription3. Please consider using the more recent version.

Product Availability

When To Use

Use the ILayerDescription interface to access read and write properties of a layer.

Members

	All Properties Methods	Description
	DefinitionExpression	The definition expression for the layer.
	ID	The layer ID. This is a unique ID for the layer, and is used to identify the layer in a number of method calls.
	ScaleSymbols	Indicates whether the layer should scale its symbols according to the reference scale.
	SelectionBufferDistance	The selection buffer distance. When drawing, and if a selection filter is specified, a buffer zone of the specified distance will be displayed around the selected features.
	SelectionColor	The selection color (used when SetSelectionSymbol = FALSE).
	SelectionFeatures	Array of selected features.
	SelectionSymbol	The selection symbol.
	SetSelectionSymbol	Indicates if the selected set of features is drawn using the SelectionSymbol.
	ShowLabels	Indicates whether the layer should display its dynamic labels.
	ShowSelectionBuffer	Indicates whether the selection buffer should be displayed.
	Visible	Indicates whether the layer is visible as defined in the TOC (i.e. marked on).

CoClasses that implement ILayerDescription

Remarks

Please note the difference of use between IMapLayerInfo and ILayerDescription: Use ILayerDescription to access layer settings that can be changed on the server object without changing the state of the underlying fine-grained ArcObjects that the layer is based on. MapLayerInfo is used to retrieve information about a layer that can only be changed by directly accessing the map document or the fine-grained ArcObjects it is based on.

In some cases you may want limit or adjust the geometry being returned in the find result. This can be done for performance reasons. Use ILayerResultOptions to manage this. If IncludeGeometry is set to False, FeatureShape returns nothing. This should increase performance in cases where feature geometry is large. You can also choose to densify or generalize the geometry returned in FeatureShape using GeometryResultOptions. Densification is used to better support clients that do not support Arcs (e.g. Bezier, Circular etc.). Generalization reduces the amount of geography being sent across the network and should lead to better performance. If LayerResultOptions are not specified for the LayerDescription, query results will include the original geometry.

Layer settings of the Server object can be permanently changed by accessing fine-grained ArcObjects. This is accomplished using IMapServerObjects. This should be done with objects in a non-pooled environment.  Changing the state of pooled objects this way will lead to unexpected results. Changes made using IMapServerObjects reside in memory only. They affect only the instance of the map service being accessed. They do not change anything in the original map document (.mxd) saved on disk. These changes exist until the service is restarted or recycled.