ArcGIS Pro 3.4 API Reference Guide
ArcGIS.Desktop.Mapping Namespace / ProportionalRendererDefinition Class / UpperSizeStop Property
Example Version

UpperSizeStop Property
Gets or sets upper size stop on the histogram.
Syntax
public Nullable<double> UpperSizeStop {get; set;}
Remarks
Histogram stops can be edited to stretch or contract the size range. Any data outside of the two stops will be treated as outliers and drawn with either the minimum or maximum size
Example
Create a Proportion Renderer with max and min symbol size capped
string colorBrewerSchemesName = "ArcGIS Colors";
StyleProjectItem style = Project.Current.GetItems<StyleProjectItem>().First(s => s.Name == colorBrewerSchemesName);
string colorRampName = "Heat Map 4 - Semitransparent";
IList<ColorRampStyleItem> colorRampList = await QueuedTask.Run(() =>
{
  return style.SearchColorRamps(colorRampName);
});
ColorRampStyleItem colorRamp = colorRampList[0];

await QueuedTask.Run(() =>
{
  CIMPointSymbol pointSym = SymbolFactory.Instance.ConstructPointSymbol(ColorFactory.Instance.GreenRGB, 1.0, SimpleMarkerStyle.Circle);
  CIMSymbolReference symbolPointTemplate = pointSym.MakeSymbolReference();

  //minimum symbol size is capped to 4 point while the maximum symbol size is set to 50 point
  ProportionalRendererDefinition prDef = new ProportionalRendererDefinition("POPULATION", symbolPointTemplate, 4, 50, true)
  {

    //setting upper and lower size stops to stop symbols growing or shrinking beyond those thresholds
    UpperSizeStop = 5000000,  //features with values >= 5,000,000 will be drawn with maximum symbol size
    LowerSizeStop = 50000    //features with values <= 50,000 will be drawn with minimum symbol size
  };
  FeatureLayer flyr = MapView.Active.Map.Layers[0] as FeatureLayer;
  CIMProportionalRenderer propRndr = flyr.CreateRenderer(prDef) as CIMProportionalRenderer;
  flyr.SetRenderer(propRndr);

});
Requirements

Target Platforms: Windows 11, Windows 10

ArcGIS Pro version: 3 or higher.
See Also