How to programatically create a line symbol with a Arrow at the endpoint.

Question

Hi

I am trying to programmatically construct a simple line symbol using ArcGIS pro sdk for .net. It should show the features with an arrow at the end node of each feature (and only at the end node). I am not sure if need to use line symbol with marker symbols (it seems a bit complicated for a relative simple symbol).

I the old ArcMap application I am migrating i had this code for the symbol

private static CartographicLineSymbolClass CreateArrowSymbol(Color c)
		{
			var color = new RgbColorClass() { Red = c.R, Green = c.G, Blue = c.B };
			var de = new SimpleLineDecorationElementClass();
			de.AddPosition(1);
			de.MarkerSymbol = new ArrowMarkerSymbolClass() { Color = color, Size = 8.0, Length = 6.0 };
			var ld = new LineDecorationClass();
			ld.AddElement(de);

var symbol = new CartographicLineSymbolClass()
			{
				Color = color,
				Width = 1.5,
				LineDecoration = ld
			};
			return symbol;
		}

Wolf · Accepted Answer

Stephen, you can also use a pre-defined arrow symbol using this code:

if (_lineSymbol == null)
{
  //Get all styles in the project
  var styleProjectItem2D = Project.Current.GetItems<StyleProjectItem>().FirstOrDefault(s => s.Name == "ArcGIS 2D");
  await QueuedTask.Run(() =>
  {
    //Get a specific project style by name
    var arrowLineSymbol = styleProjectItem2D.SearchSymbols(StyleItemType.LineSymbol, "Arrow Line 2 (Mid)")[0];
    if (arrowLineSymbol == null) return;
    _lineSymbol = arrowLineSymbol.Symbol;
  });
}

The example symbology will look like this:

I attached a sample tool code snippet that shows the symbology using a graphic overlay.

EDIT: please substitute the SearchSymbol string using the following to get an arrow at the end:

styleProjectItem2D.SearchSymbols(StyleItemType.LineSymbol, "Bold Arrow 2")[0];

StephenCochrane · Accepted Answer

Thanks a lot, Wolf.

It worked super.