Accessing a user-drawn sketch created from a custom tool

Question

In a previous post, I created a tool that allows a user to drag a rectangle on the map. The extent is then used as part of a URL to a web application query. Once the rectangle is drawn to the map, I'm unsure as to how I access the rectangle. I tried MapView.GetCurrentSketchAsync().Result, but that always returns null. Is the sketch in the map's graphic layer? Or somewhere else? Or am I missing a method?

TyroneLigon1 · Answer

Update to yesterday's post - instead of performing a "FindElement" operation on the graphics layer, I performed "GetElementsAsFlattenedList", then executed "FirstOrDefault" on the element list. Now I have the element. However, what I noticed while running in debug mode is that I can't seem to find the geometry for the element. I see there's a graphic for the element, which has a null polygon.

I'm going to try to add the geometry's extent parameters as attributes to the graphic element in the OnSketchCompleteAsync method as a last resort sans a more elegant solution.

TyroneLigon1 · Answer

Using the "Create Polygon" example, I was able to create the graphic layer with the user-drawn rectangle and add it to the map. In the section where I create the CIM polygon graphic, I add the following parameter: Name = "AOIPoly"

In a different class, when I need the extent of the shape, I run the code in the following snippet:

var mapView = MapView.Active;

GraphicsLayer gLyr = null;

GraphicElement gElem = null;

Geometry aoiGeom = null;

ArcGIS.Desktop.Framework.Threading.Tasks.QueuedTask.Run(() => {

gLyr = mapView.Map.GetLayersAsFlattenedList().OfType<GraphicsLayer>().Where(e => e.Name == "AOI Graphic").FirstOrDefault();

gElem = gLyr.FindElement("AOIPoly") as GraphicElement

aoiGeom = gElem.GetGeometry();

});

The graphics layer is found, but the graphic is not. Am I doing something wrong?

TyroneLigon1 · Answer

This question is a follow-on to this post: https://community.esri.com/t5/arcgis-pro-sdk-questions/user-drawn-rectangle-doesn-t-persist-on-map-after/m-p/1418926#M11464

Based on my experience with ArcObjects a few years ago, I suspected that I'd have to create a graphics layer and attach the shape as a graphic. I just thought that since I've been able to draw the shape on the map, and it's still visible, that there was some way to grab the geometry after the sketch was completed. I seem to remember there being a default graphics layer for the map (I might be wrong...it's been a few years), so I was hoping that was the case and I just hadn't found the reference in the SDK yet.