topic Re: Projection Points from Geographic to State Plane Coordinate system in ArcGIS API for Silverlight Questions

Projection Points from Geographic to State Plane Coordinate system

BernardNtiamoah — Tue, 05 Apr 2011 12:11:41 GMT

Here is what I want to do:
I am trying to project lat/lon points to state plane using geometry service. Everything works great but then I realized that, the projected points(graphics) don't keep their original attributes. In other words, the resulted graphics have no attributes whatsover.

Here is my question:
How do you keep track of the graphics after projection if they have no attribute? I have already tried projecting the points one after the other but that's not efficient. I need to project them in batches.

I strongly need help on this please

Bernard

Re: Projection Points from Geographic to State Plane Coordinate system

JenniferNery — Sat, 11 Dec 2021 22:53:41 GMT

You can use this instead: http://help.arcgis.com/en/webapi/silverlight/apiref/ESRI.ArcGIS.Client~ESRI.ArcGIS.Client.Tasks.GeometryService~ProjectAsync%28IEnumerable%7BGraphic%7D,SpatialReference,Object%29.html. Second parameter UserToken is object. You can pass the original graphic (with attributes) here and then update its geometry from the ProjectCompleted event instead of adding the resulting graphic directly to your map, just use it's Geometry.

Something like

void geometryService_ProjectCompleted(object sender, GraphicsEventArgs e)
{
 Graphic resultGraphic = e.Results[0];
 Graphic sourceGraphic = e.UserState as Graphic;
 if (resultGraphic.Geometry.Extent != null && sourceGraphic != null)
 {
  sourceGraphic.Geometry = resultGraphic.Geometry;
  graphicsLayer.Graphics.Add(sourceGraphic);
  MyMap.PanTo(sourceGraphic.Geometry);
 }
}

Re: Projection Points from Geographic to State Plane Coordinate system

JenniferNery — Tue, 05 Apr 2011 19:44:35 GMT

You might also want to check out this blog post: http://blogs.esri.com/Dev/blogs/silverlightwpf/archive/2011/02/12/Auto_2D00_reprojecting-graphics-layers.aspx

Re: Projection Points from Geographic to State Plane Coordinate system

BernardNtiamoah — Wed, 06 Apr 2011 01:48:18 GMT

Thank you Jennifer