topic Re: Map Extension in ArcGIS API for Silverlight Questions

Map Extension

IkerBerasaluce — Wed, 23 Jun 2010 14:03:55 GMT

Hello,

I am building a web map viewer using ArcGIS Server 9.3.1 and silverlight and I have some questions about the Extent property of the esri:Map tag

<esri:Map x:Name="MyMap" Extent="505020.40653534856,502029.51516465156,4790962.577265,4789401.627435"

As the map is not showing propperly I came up with a couple of questions:
What is unit the x and y need to be for a correct map visualization?
Is there any way of changing the unit the map uses in the Extent property?

I also noticed that my overview map stops showing where the zoom is when the Extent properties is not set, is this related or maybe I have the overview map wrongly configured?

Thank you,
Iker

Re: Map Extension

dotMorten_esri — Wed, 23 Jun 2010 16:09:30 GMT

> What is unit the x and y need to be for a correct map visualization?
That depends on which layers are in your map. The first layer with a spatial reference != null will be the one defining the units.

> Is there any way of changing the unit the map uses in the Extent property?
Yes. You can explicitly set the spatial reference as part of setting the startup extent. See this sample: http://help.arcgis.com/en/webapi/silverlight/samples/start.htm#DefineMapProjection

Note however that this doesn't just change the unit used for the extent property. It ALSO changes the spatial reference of the map layers.

Re: Map Extension

IkerBerasaluce — Mon, 28 Jun 2010 12:19:06 GMT

Thank you for the answer, it was very helpful,

Iker