IOverposter Interface (ArcObjects .NET 10.6 SDK)
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IOverposter Interface

Provides access to members that place labels for features using conflict detection. Note: the IOverposter interface has been superseded byIOverposter3. Please consider using the more recent version.

Product Availability

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

Description

IOverposter is an interface for placing labels and symbols implemented by BasicOveposter (aka the ESRI Standard Label Engine).  Follow this general sequence of steps when using this interface:

1. Call AddClass for each class to initialize properties for each class.  (InsertClass, RemoveClass, and ResetClasses help manage the classes.)
2. Use Initialize to set up the current extent and display.
3. Call AddBarrier, AddLabel, and/or AddSymbol for each participating feature.
4. Call PlaceObjects to make sure all objects are placed.
5. Use NextPlaced, NextUnplaced, and/or NextUnused to get placed object locations.  You will probably want to draw them as you get them.
6. Call ReleaseResources.

 

This interface is designed for low level access to the placement algorithms of the BasicOverposter.  The labeling maps and features, use the AnnotateMap and AnnoateFeature objects.  They wrap calls to the BasicOverposter into a more general form for use with layers and maps.

When To Use

The IOverposter interface is a low level interface for managing conflict detection when labeling features.

Members

Name Description
Method AddBarriers Adds a barrier object that placed objects must avoid.
Method AddClass Adds a class to the overposter and specifies its properties.
Method AddCurvedLabel Adds a curved label object to be placed.
Method AddLabel Adds a label object to be placed.
Method AddSymbol Adds a symbol to be placed.
Read-only property Capabilities Overposter capabilities for the specified layer.
Method Initialize Initializes the overposter for drawing into the specified area of the map display.
Method InsertClass Inserts a class at a specific index, and specifies its peoperties.
Method NextPlaced The next object that was successfully placed.
Method NextUnplaced The next object that was not successfully placed.
Method NextUnused The next object that was not used.
Read-only property NumberOfPlacedLabels The number of unplaced labels. Only valid after calling PlaceObjects.
Read-only property NumberOfUnplacedLabels The number of unplaced labels. Only valid after calling PlaceObjects.
Read-only property NumClasses The number of classes.
Method PlaceObjects Places objects using the overposter.
Method ReleaseResources Releases current objects from memory.
Method RemoveClass Removes the class at the specified index from the overposter.
Method ResetClasses Removes all classes from the overposter.

CoClasses that implement IOverposter

CoClasses and Classes Description
BasicOverposter An engine that places labels for features using conflict detection.