C3d Label Styles

Civil 3D Label Styles

Use this skill when creating, modifying, or querying label styles for any Civil 3D element (points, alignments, pipes, structures, etc.).

Label Style Overview

All Civil 3D annotations are governed by LabelStyle objects. A label style can include text labels, tick marks, lines, markers, direction arrows, reference text, and text-for-each components. Label styles support parent-child hierarchies where child styles inherit from their parent.

Pipe and Pressure Network Label Style Navigation

Gravity and pressure networks each have their own label style trees. Access them from doc.Styles.LabelStyles:

var labelStylesRoot = doc.Styles.LabelStyles;

// ── Gravity pipe label styles ──────────────────────────────────────────────
var pipeLabelStyles = labelStylesRoot.PipeLabelStyles;
var planProfileStyles  = pipeLabelStyles.PlanProfileLabelStyles;   // plan + profile labels
var crossSectionStyles = pipeLabelStyles.CrossSectionLabelStyles;  // cross-section labels

// Gravity structure label styles (flat collection)
var structLabelStyles = labelStylesRoot.StructureLabelStyles;
foreach (ObjectId styleId in structLabelStyles.LabelStyles)
{
    LabelStyle style = tr.GetObject(styleId, OpenMode.ForRead) as LabelStyle;
}

// ── Pressure network label styles ─────────────────────────────────────────
var pressurePipeStyles = labelStylesRoot.GetPressurePipeLabelStyles();
var pressPlanProfile    = pressurePipeStyles.PlanProfileLabelStyles;   // plan + profile
var pressCrossSection   = pressurePipeStyles.CrossingSectionLabelStyles; // section

var pressureFittingStyles = labelStylesRoot.GetPressureFittingLabelStyles();
foreach (ObjectId styleId in pressureFittingStyles.LabelStyles) { /* ... */ }

var pressureAppurtenanceStyles = labelStylesRoot.GetPressureAppurtenanceLabelStyles();
foreach (ObjectId styleId in pressureAppurtenanceStyles.LabelStyles) { /* ... */ }

Label Class Hierarchy

Creating a Label Style

CivilDocument doc = CivilApplication.ActiveDocument;

// Point label style
ObjectId labelStyleId = doc.Styles.LabelStyles
    .PointLabelStyles.LabelStyles.Add("NewPointLabelStyle");

// Copy an existing style as a sibling (same parent)
LabelStyle existing = ts.GetObject(existingStyleId, OpenMode.ForRead) as LabelStyle;
ObjectId copyId = existing.CopyAsSibling("CopiedStyleName");

Label Style Hierarchy (Parent/Child)

Label styles support a parent-child tree. Child styles inherit settings from their parent.

LabelStyle parentStyle = ts.GetObject(parentStyleId, OpenMode.ForWrite) as LabelStyle;

// Add a child style
ObjectId childId = parentStyle.AddChild("ChildStyleName");

// Query children
int childCount = parentStyle.ChildrenCount;
ObjectId firstChildId = parentStyle[0];           // by index
ObjectId namedChildId = parentStyle["ChildName"];  // by name

// Get parent
ObjectId parentId = parentStyle.ParentLabelStyleId;

// Get all descendants (children, grandchildren, etc.)
ObjectIdCollection allDescendants = parentStyle.GetDescendantIds();

// Remove children
parentStyle.RemoveChild(0);                // by index
parentStyle.RemoveChild("ChildStyleName"); // by name
parentStyle.RemoveAllDescendants();        // remove entire subtree

Label Style Properties (LabelStyleBase)

Access label-level properties through LabelStyle.Properties:

LabelStyle oLabelStyle = ts.GetObject(styleId, OpenMode.ForWrite) as LabelStyle;
LabelStyleBase props = oLabelStyle.Properties;

// Label settings
props.Label.Visibility.Value = true;
props.Label.Layer.Value = "C-ANNO";
props.Label.TextStyle.Value = "Standard";
props.Label.DisplayMode.Value = LabelDisplayModeType.AsComposed;

// Behavior settings
props.Behavior.OrientationReference.Value = OrientationReferenceType.WorldCoordinateSystem;
props.Behavior.InsertOption.Value = LabelInsertionType.InTheMiddleOfCurve;
props.Behavior.InsideCurveOption.Value = LabelInsideCurveType.InsideCurve;

// Plan readability
props.PlanReadability.PlanReadable.Value = true;
props.PlanReadability.PlanReadableBias.Value = 1.5708; // radians (90 degrees)
props.PlanReadability.FlipAnchorsWithText.Value = true;

// Leader settings
props.Leader.Visibility.Value = true;
props.Leader.Shape.Value = LeaderShapeType.StraightLeader;
props.Leader.ArrowheadStyle.Value = "Closed Filled";
props.Leader.ArrowheadSize.Value = 0.1;
props.Leader.Color.Value = Autodesk.AutoCAD.Colors.Color.FromColorIndex(
    Autodesk.AutoCAD.Colors.ColorMethod.ByAci, 7);

// Dragged state components
props.DraggedStateComponents.DisplayType.Value = LabelContentDisplayType.AsComposed;
props.DraggedStateComponents.BorderVisibility.Value = true;
props.DraggedStateComponents.BorderType.Value = TextBorderType.Rectangular;
props.DraggedStateComponents.TextHeight.Value = 0.08;
props.DraggedStateComponents.Gap.Value = 0.01;
props.DraggedStateComponents.UseBackgroundMask.Value = true;
props.DraggedStateComponents.LeaderAttachment.Value = LeaderAttachmentType.TopOfTopLine;
props.DraggedStateComponents.LeaderJustification.Value = true;

Label Style Component Types

Components are the building blocks of a label:

Use IsSupportedComponent() to check whether a component type is valid for a given label style before adding it.

Adding Components

// Check if a component type is supported before adding
if (oLabelStyle.IsSupportedComponent(LabelStyleComponentType.Tick))
{
    oLabelStyle.AddComponent("New Tick", LabelStyleComponentType.Tick);
}

// Add a line component
ObjectId lineComponentId = oLabelStyle.AddComponent(
    "New Line Component", LabelStyleComponentType.Line);

// ReferenceText requires a selected type parameter
ObjectId refTextId = oLabelStyle.AddReferenceTextComponent(
    "Ref Surface Elev", ReferenceTextComponentSelectedType.Surface);
// ReferenceTextComponentSelectedType values: Alignment, CogoPoint, Parcel, Profile, Surface

// TextForEach requires a selected type parameter
ObjectId textForEachId = oLabelStyle.AddTextForEachComponent(
    "Curve Data", TextForEachComponentSelectedType.Curve);
// TextForEachComponentSelectedType values: Curve, Spiral, CurveOrSpiral,
//   StructureAllPipes, StructureInFlowPipes, StructureOutFlowPipes,
//   IntersectionAllAlignment

Removing Components

// Remove a component by name
oLabelStyle.RemoveComponent("Old Text Component");

Querying Components

// Get total component count (all types)
int totalCount = oLabelStyle.GetComponentsCount();

// Get count of text components
int textCount = oLabelStyle.GetComponentsCount(LabelStyleComponentType.Text);

// Get all text components
ObjectIdCollection textComps = oLabelStyle.GetComponents(
    LabelStyleComponentType.Text);

// Access first text component
var textComp = ts.GetObject(textComps[0], OpenMode.ForWrite)
    as LabelStyleTextComponent;

Component Draw Order

Control the visual stacking order of components:

// Get current draw order
ObjectId[] drawOrder = oLabelStyle.GetComponentsDrawOrder();

// Swap two components by index
oLabelStyle.SwitchComponentsDrawOrder(0, 2);

// Set the entire draw order at once
oLabelStyle.SetComponentsDrawOrder(new ObjectId[] { id1, id2, id3 });

Check for Existing Components (Ambient Settings)

New label styles inherit components from ambient settings. Always check before adding:

if (oLabelStyle.GetComponentsCount(LabelStyleComponentType.Text) == 0)
{
    oLabelStyle.AddComponent("New Text", LabelStyleComponentType.Text);
}

// Then modify the first one:
ObjectIdCollection textCompCol = oLabelStyle.GetComponents(
    LabelStyleComponentType.Text);
var newTextComponent = ts.GetObject(textCompCol[0], OpenMode.ForWrite)
    as LabelStyleTextComponent;

Text Component Properties

var textComp = ts.GetObject(textCompId, OpenMode.ForWrite)
    as LabelStyleTextComponent;

// General
textComp.General.Visible.Value = true;
textComp.General.Name = "My Text";
textComp.General.AnchorLocation.Value = /* AnchorLocationType value */;
textComp.General.AnchorComponent.Value = "Feature";
textComp.General.UsedIn.Value = LayoutModeType.PlanAndProfile;
textComp.General.SpanOutsideSegments.Value = false;

// Text
textComp.Text.Contents.Value = "<[Station Value(Uft|FS|P2|RN|AP|Sn|TP|B2|EN|W0|OF)]>";
textComp.Text.Height.Value = 0.08;
textComp.Text.MaxWidth.Value = 0.0;
textComp.Text.Angle.Value = 0.0;
textComp.Text.XOffset.Value = 0.0;
textComp.Text.YOffset.Value = -0.01;
textComp.Text.Attachment.Value = LabelTextAttachmentType.TopCenter;
textComp.Text.Color.Value = Autodesk.AutoCAD.Colors.Color.FromColorIndex(
    Autodesk.AutoCAD.Colors.ColorMethod.ByAci, 2);

// Border
textComp.Border.Visible.Value = true;
textComp.Border.BorderType.Value = TextBorderType.Rectangular;
textComp.Border.Gap.Value = 0.005;
textComp.Border.BackgroundMask.Value = true;
textComp.Border.Color.Value = Autodesk.AutoCAD.Colors.Color.FromColorIndex(
    Autodesk.AutoCAD.Colors.ColorMethod.ByAci, 7);

Line Component Properties

var lineComp = ts.GetObject(lineCompId, OpenMode.ForWrite)
    as LabelStyleLineComponent;

// General
lineComp.General.Visible.Value = true;
lineComp.General.Name = "My Line";
lineComp.General.StartAnchorPoint.Value = /* AnchorLocationType value */;
lineComp.General.StartPointAnchorComponent.Value = "Feature";
lineComp.General.UseEndPointAnchor.Value = true;
lineComp.General.EndAnchorPoint.Value = /* AnchorLocationType value */;
lineComp.General.EndPointAnchorComponent.Value = "My Text";
lineComp.General.UsedIn.Value = LayoutModeType.PlanAndProfile;

// Line
lineComp.Line.LengthType.Value = LabelStyleLengthType.Fixed;  // Fixed or PercentOfLabel
lineComp.Line.FixedLength.Value = 0.015;
lineComp.Line.PercentLength.Value = 50.0;  // used when LengthType is PercentOfLabel
lineComp.Line.Angle.Value = 2.094; // radians = 120 degrees
lineComp.Line.StartPointXOffset.Value = 0.005;
lineComp.Line.StartPointYOffset.Value = -0.005;
lineComp.Line.EndPointXOffset.Value = 0.0;
lineComp.Line.EndPointYOffset.Value = 0.0;
lineComp.Line.Color.Value = Autodesk.AutoCAD.Colors.Color.FromColorIndex(
    Autodesk.AutoCAD.Colors.ColorMethod.ByAci, 40);

Note: LabelStyleLineComponent.StyleLine.Length is deprecated since Civil 2012. Use FixedLength with LengthType set to LabelStyleLengthType.Fixed instead.

Block Component Properties

var blockComp = ts.GetObject(blockCompId, OpenMode.ForWrite)
    as LabelStyleBlockComponent;

// General
blockComp.General.Visible.Value = true;
blockComp.General.Name = "My Block";
blockComp.General.AnchorLocation.Value = /* AnchorLocationType value */;
blockComp.General.AnchorComponent.Value = "Feature";
blockComp.General.UsedIn.Value = LayoutModeType.PlanAndProfile;

// Block
blockComp.Block.BlockName.Value = "MyBlockDef";
blockComp.Block.BlockHeight.Value = 0.1;
blockComp.Block.RotationAngle.Value = 0.0;
blockComp.Block.Attachment.Value = BlockAttachmentType.MiddleCenter;
blockComp.Block.XOffset.Value = 0.0;
blockComp.Block.YOffset.Value = 0.0;
blockComp.Block.Color.Value = Autodesk.AutoCAD.Colors.Color.FromColorIndex(
    Autodesk.AutoCAD.Colors.ColorMethod.ByAci, 1);

Tick Component Properties

var tickComp = ts.GetObject(tickCompId, OpenMode.ForWrite)
    as LabelStyleTickComponent;

// General
tickComp.General.Visible.Value = true;
tickComp.General.Name = "My Tick";

// Tick (uses block definitions for tick marks)
tickComp.Tick.BlockName.Value = "TickBlock";
tickComp.Tick.BlockHeight.Value = 0.05;
tickComp.Tick.RotationAngle.Value = 0.0;
tickComp.Tick.AlignWithObject.Value = true;
tickComp.Tick.Color.Value = Autodesk.AutoCAD.Colors.Color.FromColorIndex(
    Autodesk.AutoCAD.Colors.ColorMethod.ByAci, 3);

Direction Arrow Component Properties

var arrowComp = ts.GetObject(arrowCompId, OpenMode.ForWrite)
    as LabelStyleDirectionArrowComponent;

// General
arrowComp.General.Visible.Value = true;
arrowComp.General.Name = "My Arrow";
arrowComp.General.AnchorLocation.Value = /* AnchorLocationType value */;
arrowComp.General.AnchorComponent.Value = "Feature";
arrowComp.General.UsedIn.Value = LayoutModeType.PlanAndProfile;
arrowComp.General.SpanOutsideSegments.Value = false;

// Direction Arrow
arrowComp.DirectionArrow.ArrowheadStyle.Value = "Closed Filled";
arrowComp.DirectionArrow.ArrowheadSize.Value = 0.1;
arrowComp.DirectionArrow.FixedLength.Value = true;
arrowComp.DirectionArrow.LengthOrMinimumLength.Value = 0.3;
arrowComp.DirectionArrow.RotationAngle.Value = 0.0;
arrowComp.DirectionArrow.XOffset.Value = 0.0;
arrowComp.DirectionArrow.YOffset.Value = 0.0;
arrowComp.DirectionArrow.Color.Value = Autodesk.AutoCAD.Colors.Color.FromColorIndex(
    Autodesk.AutoCAD.Colors.ColorMethod.ByAci, 5);

Reference Text Component

Reference text pulls property fields from another Civil 3D object (alignment, point, parcel, profile, or surface). It inherits all StyleText and StyleBorder properties from the text component.

// Must use the specialized add method
ObjectId refId = oLabelStyle.AddReferenceTextComponent(
    "Surface Elev", ReferenceTextComponentSelectedType.Surface);
var refComp = ts.GetObject(refId, OpenMode.ForWrite)
    as LabelStyleReferenceTextComponent;

// Read-only: which object type this references
string objType = refComp.General.ReferenceTextObjectType;

// Text and Border properties work identically to LabelStyleTextComponent
refComp.Text.Contents.Value = "ELEV=<[Surface Elevation(Uft|P2|RN|AP|Sn|OF)]>";
refComp.Text.Height.Value = 0.08;
refComp.Border.Visible.Value = false;

TextForEach Component

Repeats text for each curve, spiral, or pipe in the labeled feature. It inherits text/border properties from the text component and adds content fields for curves and spirals.

// Must use the specialized add method
ObjectId tfeId = oLabelStyle.AddTextForEachComponent(
    "Curve Info", TextForEachComponentSelectedType.CurveOrSpiral);
var tfeComp = ts.GetObject(tfeId, OpenMode.ForWrite)
    as LabelStyleTextForEachComponent;

// Read-only: what this iterates over
string iterType = tfeComp.General.TextForEach;

// Separate content strings for curves and spirals
tfeComp.Text.Contents.Value = "Default text";
tfeComp.Text.CurveContents.Value = "R=<[Radius(Uft|P2|RN|AP|Sn|OF)]>";
tfeComp.Text.SpiralContents.Value = "L=<[Spiral Length(Uft|P2|RN|AP|Sn|OF)]>";

Property Fields in Label Text

Text content uses property fields with the format:

<[Property name (modifier1|modifier2|...|modifierN)]>

Modifiers are optional, can be in any order. Multiple fields can be combined with normal text.

var textComp = ts.GetObject(textCompCol[0], OpenMode.ForWrite)
    as LabelStyleTextComponent;

// Design speed and station
textComp.Text.Contents.Value = "SPD=<[Design Speed(P0|RN|AP|Sn)]>";
textComp.Text.Contents.Value += " STA=<[Station Value(Uft|FS|P2|RN|AP|Sn|TP|B2|EN|W0|OF)]>";

Common Property Field Modifiers

Point Label Property Fields

<[Name(CP)]>
<[Point Number]>
<[Northing(Uft|P4|RN|AP|Sn|OF)]>
<[Easting(Uft|P4|RN|AP|Sn|OF)]>
<[Raw Description(CP)]>
<[Full Description(CP)]>
<[Point Elevation(Uft|P3|RN|AP|Sn|OF)]>
<[Latitude(Udeg|FDMSdSp|P6|RN|DPSn|CU|AP|OF)]>
<[Longitude(Udeg|FDMSdSp|P6|RN|DPSn|CU|AP|OF)]>
<[Grid Northing(Uft|P4|RN|AP|Sn|OF)]>
<[Grid Easting(Uft|P4|RN|AP|Sn|OF)]>

Alignment Label Property Fields

<[Station Value(Uft|FS|P0|RN|AP|Sn|TP|B2|EN|W0|OF)]>
<[Raw Station(Uft|FS|P2|RN|AP|Sn|TP|B2|EN|W0|OF)]>
<[Northing(Uft|P4|RN|AP|Sn|OF)]>
<[Easting(Uft|P4|RN|AP|Sn|OF)]>
<[Design Speed(P3|RN|AP|Sn|OF)]>
<[Alignment Name(CP)]>
<[Alignment Description(CP)]>
<[Alignment Length(Uft|P3|RN|AP|Sn|OF)]>
<[Alignment Start Station(Uft|FS|P2|RN|AP|Sn|TP|B2|EN|W0|OF)]>
<[Alignment End Station(Uft|FS|P2|RN|AP|Sn|TP|B2|EN|W0|OF)]>

Sharing Styles Between Drawings

Export styles to another open drawing:

// Export a single style
ObjectId styleId = doc.Styles.LabelStyles
    .AlignmentLabelStyles.MajorStationLabelStyles[0];
LabelStyle style = ts.GetObject(styleId, OpenMode.ForRead) as LabelStyle;

Database destDb = null;
foreach (Document d in Application.DocumentManager)
{
    if (d.Name.Equals("Drawing1.dwg")) destDb = d.Database;
}

// StyleConflictResolverType: how to handle name conflicts
style.ExportTo(destDb, StyleConflictResolverType.Override);

// Export collections of styles
StyleBase.ExportTo(styleCollection, destDb, StyleConflictResolverType.Override);

Default Label Style Settings

Each LabelStyleCollection has a DefaultLabelStyle that controls ambient defaults for new label styles:

LabelStyleCollection coll = doc.Styles.LabelStyles
    .PointLabelStyles.LabelStyles;

LabelStyleDefault defaults = coll.DefaultLabelStyle;
defaults.Label.TextStyle.Value = "Standard";
defaults.Label.Visibility.Value = true;
defaults.Components.TextHeight.Value = 0.08;
defaults.Leader.Visibility.Value = false;
defaults.Behavior.OrientationReference.Value =
    OrientationReferenceType.WorldCoordinateSystem;
defaults.PlanReadability.PlanReadable.Value = true;

// Access expressions defined for this collection
ExpressionCollection expressions = coll.Expressions;

Label Style Filtering (from this codebase)

The LabelFilterHelper class in SharedTypes.cs filters label styles by:

• View type keyword (e.g., "Plan", "Profile", "Section")
• Parts list prefix (e.g., "P_Sanitary" -> "U_P")

Gotchas

• New label styles are initialized from ambient settings - may already contain components
• Use IsSupportedComponent() to verify a component type is valid before adding it; adding an unsupported type may compile but produce no visible result
• Labels depend on graphical objects (blocks) that may not exist in the current document
• The .Value pattern applies to all label properties (e.g., component.General.Visible.Value = true)
• Ambient settings determine units - account for different drawings having different unit settings
• Duplicate component names throw ArgumentException
• LabelStyleLineComponent.StyleLine.Length is deprecated since Civil 3D 2012 - use FixedLength with LengthType instead
• ReferenceText and TextForEach components must be added via their specialized methods (AddReferenceTextComponent / AddTextForEachComponent), not the generic AddComponent
• Component names passed to RemoveComponent() must match exactly (case-sensitive)

Related Skills

• c3d-root-objects - Accessing styles through CivilDocument
• c3d-pipe-networks - Pipe and pressure network label creation (uses styles from this skill)
• c3d-sample-lines - Section view label creation (PipeSectionLabel, PressurePipeSectionLabel, etc.)
• c3d-alignments - Alignment label set styles
• c3d-points - Point label styles and description keys