ArcGIS Developer Help

ILineLabelPosition Interface

Provides access to members that control the relative position of line labels.

Product Availability

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

Description

The properties of this interface correspond to the settings on the label placement properties dialog in ArcMap for line features. These properties are also used for feature-linked annotation.

When To Use

Manages label placement properties for line features. For example, you can use this interface to specify whether labels can be placed above, below and/or centered on the line features being labeled.

Members

	Name	Description
	Above	Indicates if labels are placed above lines.
	AtEnd	Indicates if labels are placed at the end of lines.
	AtStart	Indicates if labels are placed at the start of lines.
	Below	Indicates if labels are placed below lines.
	Horizontal	Indicates if labels are placed horizontally.
	InLine	Indicates if labels are placed along lines at the best position.
	Left	Indicates if labels are placed to the left of lines.
	Offset	Offset from the start/end of lines (in map units).
	OnTop	Indicates if labels are placed on top of lines.
	Parallel	Indicates if labels are placed parallel to lines.
	Perpendicular	Indicates if labels are placed perpendicular to lines.
	ProduceCurvedLabels	Indicates if labels follow lines.
	Right	Indicates if labels are placed to the right of lines.

Classes that implement ILineLabelPosition

Classes	Description
LineLabelPosition	Controls the relative positions of line labels.

Remarks

Not all property value combinations are valid in ArcMap, but no validation is performed by this object. This means that you can set the properties of this object to any combination of true/false and this object will not change them for you.

When labeling occurs in ArcMap, invalid property combinations on this object can create unexpected results.

Validation does occur when the ArcMap user interface is used (i.e. the label placement properties dialog). Changes applied here by the user will change the values set on the current object.

When setting properties using this interface, it is recommended that you use the ArcMap user interface logic as a guide to setting valid property combinations. Several of these rules are described here:

Horizontal, Parallel, and Perpendicular are exclusive, meaning that one and only one should be set to True. ProduceCurvedLabels should only be True only if Parallel is also True.
The property pairs Above/Below and Right/Left are exclusive. To place labels based on page orientation, use Above/Below. To place labels based on line orientation, use Right/Left. Note that within these pairs you can set either or both properties to True. To be valid, at least one must be set to True.
At Start, At End, and InLine are exclusive and at least one should be set to True. If InLine is True then each label is placed along its line feature at the best position. If InLine is False, then you can specify line placement priorities using ILineLabelPlacementPriorities.