Expression Property (CIMLabelClass)
Modify label expression using Arcade
var lyr = MapView.Active.Map.GetLayersAsFlattenedList().OfType<FeatureLayer>().FirstOrDefault(f => f.ShapeType == esriGeometryType.esriGeometryPolygon);
if (lyr == null) return;
QueuedTask.Run(() =>
{
//Get the layer's definition
//community sample Data\Admin\AdminSample.aprx
var lyrDefn = lyr.GetDefinition() as CIMFeatureLayer;
if (lyrDefn == null) return;
//Get the label classes - we need the first one
var listLabelClasses = lyrDefn.LabelClasses.ToList();
var theLabelClass = listLabelClasses.FirstOrDefault();
//set the label class Expression to use the Arcade expression
theLabelClass.Expression = "return $feature.STATE_NAME + TextFormatting.NewLine + $feature.POP2000;";
//Set the label definition back to the layer.
lyr.SetDefinition(lyrDefn);
});
Target Platforms: Windows 11, Windows 10
ArcGIS Pro version: 3 or higher.