ArcObjects Library Reference (Carto)  

ILevelRenderer Interface

Provides access to members that control the drawing of symbols for features, where symbols are separated into levels, and each level drawn separately.

Product Availability

Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server.

Members

Description
Write-only property CurrentDrawLevel The current draw level, (set to -1 to draw all levels).
Read-only property LevelArray Array that contains all levels used by the symbols, (symbols without a level get a level of 0).

CoClasses that implement ILevelRenderer

CoClasses and Classes Description
ClassBreaksRenderer A renderer that can be used to draw graduated color (choropleth) and graduated symbol maps.
GeoSymRenderer (esriDefenseSolutions) Custom renderer for symbolizing data with GeoSym symbology.
NAStopRenderer (esriNetworkAnalyst) Defines symbology for rendering stops.
RepresentationRenderer A renderer that draws features using representation information stored in the layer’s data source.
SimpleRenderer A simple renderer where the same symbol is drawn for each feature.
UniqueValueRenderer A unique values renderer where symbols are assigned to features based on an unique attribute values.
UniqueValueTextRenderer (esriTrackingAnalyst) This is a feature renderer that supports rendering points using values from a field in the feature class.

Remarks

A renderer needs to implement this interface to support Symbol Level Drawing -- In ArcGIS 8.3 and and earlier versions this was known in the ArcMap user interface as Advanced Drawing Options.

When Symbol Level Drawing is enabled for a feature layer or group layer, the framework draws features by iterating through all of the symbol levels for all of the symbols levels in the layer(s). This means that features can be drawn in an order that is different from the layer order in the table of contents, and also the order of features retrieved from the feature class table(s).

To learn more about Symbol Level Drawing see the ArcGIS for Desktop Help.

You can tell if an Esri feature renderer supports Symbol Level Drawing by checking if this interface is supported.

When writing a custom feature renderer, and you want to support Symbol Level Drawing, you need to implement this interface.

Use IMapLevel to access the symbol level for a given layer of a multilayer symbol. Use ISymbolLevels::UseSymbolLevels to check if Symbol Level Drawing is on, or to turn it on or off for a given layer. To open the Symbol Levels dialog, use ISymbolLevelDialog::DoModal.