topic Re: Getting custom legend info. in ArcGIS API for Silverlight Questions

Getting custom legend info.

jonataspovoas — Wed, 14 Dec 2011 14:49:46 GMT

Hi,

I'm doing a Silvelight application, and in it I need to get the info about the legend of the map, so I can add it on a printing funtionality. I know that the esri legend class gets it from the rest service (something like http://server/ArcGIS/rest/services/Folder/Service/MapServer/legend) but i don't know how to get this list myself, and i need to get a specific list of items from it (the ones been used - the info about what's shown on the map - at the moment the user clicks the print button).

Does anyone know how to do it?

Re: Getting custom legend info.

JenniferNery — Wed, 14 Dec 2011 16:12:00 GMT

Are you talking about this Print sample? http://help.arcgis.com/en/webapi/silverlight/3.0/samples/start.htm#ExportWebMap.

This sample use our Legend control http://help.arcgis.com/en/webapi/silverlight/3.0/samples/start.htm#LegendWithTemplates. The legend displays symbols from layer renderer. If you modify this sample to apply a different renderer to the FeatureLayer, this will be used by Legend control. If you want to get to the service-defined renderer, when the layer is initialized, you can check LayerInfo.Renderer.

Re: Getting custom legend info.

jonataspovoas — Wed, 14 Dec 2011 16:44:44 GMT

Are you talking about this Print sample? http://help.arcgis.com/en/webapi/silverlight/3.0/samples/start.htm#ExportWebMap.

I hadn't seen this sample. Also, I couldn't make it work, when i click at the button nothing happens...

This sample use our Legend control http://help.arcgis.com/en/webapi/silverlight/3.0/samples/start.htm#LegendWithTemplates. The legend displays symbols from layer renderer. If you modify this sample to apply a different renderer to the FeatureLayer, this will be used by Legend control. If you want to get to the service-defined renderer, when the layer is initialized, you can check LayerInfo.Renderer.

About the Legend, I need this information, to show on the page.

Something like this:

Re: Getting custom legend info.

DominiqueBroux — Thu, 15 Dec 2011 11:09:04 GMT

If, for any reason, you need to get the list of legend infos out of the legend control, you can use the QueryLegendInfos method that exist on all layer supporting the legend.
That being said, for your sample, you should be able to use the legend control and to retemplate it to get the expected result (for example with a WrapPanel, there is a sample here : http://www.arcgis.com/home/item.html?id=c673bf3e983b418495eeb0f45bb44c68)

Re: Getting custom legend info.

jonataspovoas — Mon, 26 Dec 2011 09:25:31 GMT

If, for any reason, you need to get the list of legend infos out of the legend control, you can use the QueryLegendInfos method that exist on all layer supporting the legend.
That being said, for your sample, you should be able to use the legend control and to retemplate it to get the expected result (for example with a WrapPanel, there is a sample here : http://www.arcgis.com/home/item.html?id=c673bf3e983b418495eeb0f45bb44c68)

Hi,

The QueryLegendInfos method do work, but it brings every legend, without the scale filter. This problem i'm already working on, but even with my code to control it, different layers may have, in my case, the same the same info, like Ocean and state limits, and that info is been shown many times in the wrappanel. Is there any way to work that around?

Re: Getting custom legend info.

DominiqueBroux — Mon, 26 Dec 2011 10:33:25 GMT

I am still thinking that you should use the legend control that will manage the scale visibility for you, else you have to do it by yourself : each LayerLegendInfo has a MaximumScale and a MinimumScale that you can use to get a visibility depending on the map scale.