ArcGIS Pro 3.4 API Reference Guide
ArcGIS.Core.CIM Namespace / CIMMaplexLabelPlacementProperties Class / SpreadWords Property
Example Version

SpreadWords Property
Gets or sets a value indicating whether to whether to spread words along line features.
Syntax
public bool SpreadWords {get; set;}
Example
Spread labels across Polygon geometry
//Note: call within QueuedTask.Run()

//Get the layer's definition
var lyrDefn = featureLayer.GetDefinition() as CIMFeatureLayer;
//Get the label classes - we need the first one
var listLabelClasses = lyrDefn.LabelClasses.ToList();
var theLabelClass = listLabelClasses.FirstOrDefault();
//Spread Labels (words and characters to fill feature)
// Spread words to fill feature
theLabelClass.MaplexLabelPlacementProperties.SpreadWords = true;
//Spread Characters to a fixed limit of 50%
theLabelClass.MaplexLabelPlacementProperties.SpreadCharacters = true;
theLabelClass.MaplexLabelPlacementProperties.MaximumCharacterSpacing = 50.0;
lyrDefn.LabelClasses = listLabelClasses.ToArray(); //Set the labelClasses back
featureLayer.SetDefinition(lyrDefn); //set the layer's definition
Requirements

Target Platforms: Windows 11, Windows 10

ArcGIS Pro version: 3 or higher.
See Also