public abstract class CIMSymbolLayer : CIMObject, System.ComponentModel.INotifyPropertyChanged, System.Xml.Serialization.IXmlSerializable  

{
    //Note: Needs QueuedTask to run
    var lineStrokeRed = SymbolFactory.Instance.ConstructStroke(ColorFactory.Instance.RedRGB, 4.0);
    var markerCircle = SymbolFactory.Instance.ConstructMarker(ColorFactory.Instance.RedRGB, 12, SimpleMarkerStyle.Circle);
    markerCircle.MarkerPlacement = new CIMMarkerPlacementOnVertices()
    {
        AngleToLine = true,
        PlaceOnEndPoints = true,
        Offset = 0
    };
    var lineSymbolWithCircles = new CIMLineSymbol()
    {
        SymbolLayers = new CIMSymbolLayer[2] { markerCircle, lineStrokeRed }
    };
}

{
      var markerTriangle = SymbolFactory.Instance.ConstructMarker(ColorFactory.Instance.RedRGB, 12, SimpleMarkerStyle.Triangle);
      markerTriangle.Rotation = -90; // or -90
      markerTriangle.MarkerPlacement = new CIMMarkerPlacementOnLine() { AngleToLine = true, RelativeTo = PlacementOnLineRelativeTo.LineEnd };

      var lineSymbolWithArrow = new CIMLineSymbol()
      {
          SymbolLayers = new CIMSymbolLayer[2] { markerTriangle,
          SymbolFactory.Instance.ConstructStroke(ColorFactory.Instance.RedRGB, 2)
}
      };
  }

/// <summary>
/// Creates Mesh procedural symbol with various textures.
/// ![MeshProceduralTexture](https://ArcGIS.github.io/arcgis-pro-sdk/images/Symbology/mesh-procedural-texture.png)
/// Note: The rule package used in this method can be obtained from the Sample Data included in the arcgis-pro-sdk-community-samples repository.
/// </summary>
{
  //Note: Run withing QueuedTask
  string _rulePkgPath = @"C:\Data\RulePackages\MultipatchTextures.rpk";
  CIMSymbolLayer[] proceduralSymbolLyr =
          {
              new CIMProceduralSymbolLayer()
              {
                  PrimitiveName = "Textures",
                  RulePackage = _rulePkgPath,
                  RulePackageName = "Textures",
              }
          };
  var meshProceduralTextureSymbol = new CIMMeshSymbol()
  {
    SymbolLayers = proceduralSymbolLyr
  };
}

/// <summary>
/// Create a polygon symbol using the ConstructHatchFill method . <br/>
/// ![PolygonSymbolDiagonalCrossHatch](https://ArcGIS.github.io/arcgis-pro-sdk/images/Symbology/ConstructHatchFill.png)
/// </summary>
{
  CIMStroke lineStroke = SymbolFactory.Instance.ConstructStroke(CIMColor.CreateRGBColor(51, 51, 51, 60), 4, SimpleLineStyle.Solid);
  //gradient
  var hatchFill = SymbolFactory.Instance.ConstructHatchFill(lineStroke, 45, 6, 0);

  List<CIMSymbolLayer> symbolLayers = new()
  {
    hatchFill
  };
  //This is the polygon symbol with a diagonal cross hatch fill
  CIMPolygonSymbol crossHatchPolygonSymbol = new CIMPolygonSymbol() { SymbolLayers = symbolLayers.ToArray() };
  //To apply the symbol to a polygon feature layer
  //var renderer = theLayer.GetRenderer() as CIMSimpleRenderer;
  //renderer.Symbol = crossHatchPolygonSymbol.MakeSymbolReference();
  //theLayer.SetRenderer(renderer);
}

/// <summary>
/// Create a polygon symbol with a dash dot fill. <br/>
/// ![PolygonSymbolDashDot](https://ArcGIS.github.io/arcgis-pro-sdk/images/Symbology/polygon-dash-dot.png)
/// </summary>
{
  //Note: Run withing QueuedTask
  var trans = 50.0;//semi transparent
  CIMStroke outline = SymbolFactory.Instance.ConstructStroke(CIMColor.CreateRGBColor(0, 0, 0, trans), 2.0, SimpleLineStyle.Solid);

  //Stroke for the fill            
  var dashDot = SymbolFactory.Instance.ConstructStroke(ColorFactory.Instance.RedRGB, 1.0, SimpleLineStyle.DashDotDot);
  //Mimic cross hatch
  CIMFill[] solidColorHatch =
        {

           new CIMHatchFill()
          {
              Enable = true,
              Rotation = 0.0,
              Separation = 2.5,
              LineSymbol = new CIMLineSymbol(){SymbolLayers = new CIMSymbolLayer[1] {dashDot } }
          },
           new CIMSolidFill()
          {
              Enable = true,
              Color = ColorFactory.Instance.CreateRGBColor(255, 255, 0)
          },
};
  List<CIMSymbolLayer> symbolLayers = [outline, .. solidColorHatch];
  //This is the polygon symbol with a dash dot fill
  CIMPolygonSymbol dashDotFillPolygon = new CIMPolygonSymbol() { SymbolLayers = symbolLayers.ToArray() };
  //To apply the symbol to a polygon feature layer
  //var renderer = theLayer.GetRenderer() as CIMSimpleRenderer;
  //renderer.Symbol = dashDotFillPolygon.MakeSymbolReference();
  //theLayer.SetRenderer(renderer);
}

/// <summary>
/// Create a polygon symbol with a gradient color fill. <br/>
/// ![PolygonSymbolGradientColor](https://ArcGIS.github.io/arcgis-pro-sdk/images/Symbology/polygon-gradient-color.png)
/// 1. Create a solid colored stroke with 50% transparency
/// 1. Create a fill using gradient colors red through green
/// 1. Apply both the stroke and fill as a symbol layer array to the new PolygonSymbol
/// </summary>
{
  //Note: Run withing QueuedTask
  var trans = 50.0;//semi transparent
  CIMStroke outline = SymbolFactory.Instance.ConstructStroke(CIMColor.CreateRGBColor(0, 0, 0, trans), 2.0, SimpleLineStyle.Solid);
  //Mimic cross hatch
  CIMFill solidColorHatch =
         new CIMGradientFill()
         {
           ColorRamp = ColorFactory.Instance.ConstructColorRamp(ColorRampAlgorithm.LinearContinuous,
                                ColorFactory.Instance.RedRGB, ColorFactory.Instance.GreenRGB)
         };
  List<CIMSymbolLayer> symbolLayers = new List<CIMSymbolLayer>
    {
              outline,
              solidColorHatch
    };

  CIMPolygonSymbol gradientColorFillPolygon = new CIMPolygonSymbol() { SymbolLayers = symbolLayers.ToArray() };
  //To apply the symbol to a polygon feature layer
  //var renderer = theLayer.GetRenderer() as CIMSimpleRenderer;
  //renderer.Symbol = gradientColorFillPolygon.MakeSymbolReference();
  //theLayer.SetRenderer(renderer);
}