How to move the center (centroid) of a circle programmatically using C# and the ArcGIS Pro SDK

Question

Is there any way to move the center (centroid) of a circle/polygon to a new X/Y on the map, such as the current mouse location in C# using the ArcGIS Pro SDK?

I have a solution that I found that builds a buffer polygon using GeometryEngine.Instance.GeodesicBuffer. It takes a point, a radius, and linear units and outputs a polygon. The results are exactly what I need, but unfortunately I have to call it on every mouse move. This causes too much overhead, because the method is very slow and the polygon drags behind the mouse. I should be able to create the geodesic buffer (polygon) once on an initial button click and then just move that buffer (polygon) at its centroid to a new location on the mouse move. However, I still cannot do this.

The following is some code that I am using to create the buffer. I just need to plug in a moue point on the buffer to center it.

System.Drawing.Point currentLoc = System.Windows.Forms.Control.MousePosition;
MapPoint mapPt = MapView.Active.ScreenToMap(new Point(currentLoc.X, currentLoc.Y));
ArcGIS.Core.Geometry.Geometry buffer = GeometryEngine.Instance.GeodesicBuffer(mapPt, _graphics[i].Radius, GetLinearUnits(_graphics[i].Units));
if (_graphics[i].Graphic == null)
{
    _graphics[i].Graphic = MapView.Active.AddOverlay(buffer, _graphics[i].Symbol);
}
else
{
    MapView.Active.UpdateOverlay(_graphics[i].Graphic, buffer, _graphics[i].Symbol);
}

Answer 1

I have devised a solution for this problem with the assistance of the Esri ArcGIS Pro SDK team. I am utilizing the GeometryEngine.Instance.Move method on the polygon along with a delta X and delta Y coordinate. The previous mouse point X/Y is subtracted from the current mouse point X/Y. This creates the delta that is needed to move the centroid of the polygon to the correct location. The following is the necessary code:

MapPoint screenMapPt = MapView.Active.ScreenToMap(new Point(e.X, e.Y));
MapPoint prevPt = MapView.Active.ScreenToMap(new Point(_prevX, _prevY));

ArcGIS.Core.Geometry.Geometry buffer = GeometryEngine.Instance.Move(_graphics[i].Polygon, (screenMapPt.X - prevPt.X), (screenMapPt.Y - prevPt.Y));
_graphics[i].Polygon = (Polygon)buffer;

The code is still a little bit laggy, since it all happens on the mouse move event, but it is faster than the previous option of creating a GeodesicBuffer.

Thanks again to the Esri ArcGIS Pro SDK team.