topic Re: How to Get polygon points from Geometry.Ring in ArcGIS API for Silverlight Questions

How to Get polygon points from Geometry.Ring

JulieBiju — Tue, 26 Jun 2012 02:18:07 GMT

Hello...Advance thanks...Please help me to solve the issue specified below

I drw a polygon on my map using the function below.Now i want to save these polygon points to DB for future reference.How can i retrive polygon points?I try to access the ring values and failed with that .Help me for this Please

Private Sub MyDrawObject_DrawComplete(ByVal sender As Object, ByVal args As ESRI.ArcGIS.Client.DrawEventArgs)                   'args.Geometry.rings              Dim graphicsLayer As GraphicsLayer = TryCast(MyMap.Layers("MyGraphicsLayer"), GraphicsLayer)         Dim graphic As New ESRI.ArcGIS.Client.Graphic() With           {             .Geometry = args.Geometry,             .Symbol = _activeSymbol           }         graphicsLayer.Graphics.Add(graphic)       End Sub

Re: How to Get polygon points from Geometry.Ring

JoeHershman — Tue, 26 Jun 2012 02:50:45 GMT

You cast the geometry to a Polygon, which has a collection of Rings. Each Ring is a PointCollection, for a user drawn polygon with the standard tools the polygon will only have one Ring. In C# something like this

    if ( args.Geometry is Polygon )   {   PointCollection points = ((Polygon)geometry).Rings[0];   foreach ( MapPoint mapPoint in points )   {    //Save the points   }  }

Hope that helps

Re: How to Get polygon points from Geometry.Ring

JulieBiju — Sat, 11 Dec 2021 11:54:41 GMT

You cast the geometry to a Polygon, which has a collection of Rings. Each Ring is a

if ( args.Geometry is Polygon )
{
PointCollection points = ((Polygon)geometry).Rings[0];
foreach ( MapPoint mapPoint in points )
{
//Save the points
}
}

I am getting errors like
'Polygon' is ambiguous, imported from the namespaces or types 'ESRI.ArcGIS.Client.Geometry, System.Windows.Shapes'.
'PointCollection' is ambiguous, imported from the namespaces or types 'ESRI.ArcGIS.Client.Geometry, System.Windows.Media'.

 If TypeOf args.Geometry Is Polygon Then
            Dim points As PointCollection = DirectCast(geometry, Polygon).Rings(0)
            'Save the points
            For Each mapPoint As MapPoint In points
            Next
        End If

Re: How to Get polygon points from Geometry.Ring

JulieBiju — Tue, 26 Jun 2012 03:18:49 GMT

I am getting errors like
'Polygon' is ambiguous, imported from the namespaces or types 'ESRI.ArcGIS.Client.Geometry, System.Windows.Shapes'.
'PointCollection' is ambiguous, imported from the namespaces or types 'ESRI.ArcGIS.Client.Geometry, System.Windows.Media'.

Commented
'Imports System.Windows.Media
'Imports System.Windows.Shapes

Now working fine...Thankk UUUUU

Re: How to Get polygon points from Geometry.Ring

DavidMarley — Sat, 11 Dec 2021 11:54:44 GMT

That "ambiguous...namespace" error is a very standard one and simply means there are multiple objects with name = <ObjectName> (e.g., Polygon) in the namespaces you have referenced via using statements. One solution is as you noted, to simply remove any using statements for namespaces you are not using anyway. The other solution is to fully qualify the object reference, for example "ESRI.ArcGIS.Client.Geometry.Polygon" instead of just "Polygon". One last handy solution is to use the following using syntax to clarify which object you intend to use by default in your class:

using Polygon = ESRI.ArcGIS.Client.Geometry.Polygon;

Then in your code you can refer to Polygon without getting any ambiguous namespace error:

Polygon poly = new Polygon(); // no ambiguous error...

This is especially useful for something like Polygon which has naming conflicts even within the Esri namespaces (e.g., ESRI.ArcGIS.Client.Geometry.Polygon and ESRI.ArcGIS.Client.Bing.GeocodeService.Polygon)