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System.ArgumentException 'An item with the same key has already been added'

Question asked by on Jan 5, 2017
Latest reply on Jun 15, 2018 by mnielsen-esristaff

How can I diagnose the above exception? In my code, I roughly do the following:


1. Create an overlay ( overlay = new GraphicsOverlay() )

2. Create a set of polygons ( poly = new Polygon(mappoints) where mappoints is a PointCollection)

3. Create a graphic with the polygon geometry and a simple fill symbol for each polygon

   ( graphic = new Graphic() { Geometry = poly, Symbol = new SimpleFillSymbol() { Color = Colors.Red } } )

4. Add that graphic to the overlay. ( overlay.Add(graphic) )

Then, when something changes, I will call overlay.Graphics.Clear(), then repeat steps 2-3.


When I do this, sometimes on the new Graphic(...), I will get the exception (but not every time)


I'm using Esri.ArcGISRuntime version

Any idea what's going on?