topic problem wit result of field task in ArcGIS API for Silverlight Questions

problem wit result of field task

MarcoRosa — Mon, 28 Feb 2011 13:12:45 GMT

Hi to all, i've an error at the end of field task, in the FindDetails_SelectionChanged of my datagrid output.
If i find a polygon or a line all works good , if i find a point i have an error on the red istruction below when i try to obtain shape type.
Maybe a spatial reference problem ? I'm using a find task on a service with a point layer inside. the layer spatial reference is 3857 and the map is 102100.
The error is "Object reference not set to an instance of an object."
What can it be ?

Thanks GP

DataGrid dataGrid = sender as DataGrid;

int selectedIndex = dataGrid.SelectedIndex;
if (selectedIndex > -1)
{
FindResult findResult = (FindResult)
_Parent.MyDataGridOutput.QueryDetailsDataGrid.SelectedItem;
Graphic graphic = findResult.Feature;

switch (graphic.Attributes["Shape"].ToString())
{
case "Polygon":
graphic.Symbol = LayoutRoot.Resources["DefaultFillSymbol"] as ESRI.ArcGIS.Client.Symbols.Symbol;
break;
case "Polyline":
graphic.Symbol = _Parent.LayoutRoot.Resources["DefaultLineSymbol"] as ESRI.ArcGIS.Client.Symbols.Symbol;
break;
case "Point":
graphic.Symbol = _Parent.LayoutRoot.Resources["DefaultMarkerSymbol"] as ESRI.ArcGIS.Client.Symbols.Symbol;
break;
}

Re: problem wit result of field task

JenniferNery — Mon, 28 Feb 2011 18:38:26 GMT

These two spatial reference are equivalent. Does your service include Shape field for points?

Kindly check that
graphic.Attributes["Shape"]
is not null before you, call ToString() on it.

Re: problem wit result of field task

MarcoRosa — Tue, 01 Mar 2011 12:15:30 GMT

Hi Jennifer,
i have deleted the service and recreate a new one with other point , same spatial reference , same all. Strange but this works ... now im' trying other points layer and i'll see.
Thanks at the moment.
see un on other posts 🙂 have nice day

Re: problem wit result of field task

ErikEngstrom — Tue, 29 Mar 2011 17:26:52 GMT

Keep in mind that the line:

switch (graphic.Attributes["Shape"].ToString())

"Shape" is case sensitive. If you have a feature class that has the Shape field as "SHAPE" (all uppercase), you'll need to accommodate for that in your code, or else you will receive an error.