topic Working With Parcels in ArcGIS API for Silverlight Questions

Working With Parcels

BrianGustafson — Wed, 23 Feb 2011 15:56:43 GMT

Is there a good way to work with large amounts of data, like a parcel layer? We are collecting parcel information for a four state area and I want to give the users the ability to load the data that they need to work with. When I try and use a feature layer it takes a long time to load and then when I pan or zoom the app freezes while the data is refreshed. What is the best way to dnamically load and display large amounts of features?

Re: Working With Parcels

dotMorten_esri — Fri, 25 Feb 2011 06:10:29 GMT

The trick is to load as little data to the client as possible. For instance not load more than you need, and download more data (ie all the attributes, high resolution data etc) as the user asks for it. Set outfields to only ObjectID, use OnDemand mode, only display features when zoomed far enough in, and use MaxAllowableOffset to reduce the number of vertices transferred to the client.
Or even something as simple as using a dynamic layer instead of a featurelayer, and use click to perform identify when the user demands it (do you REALLY need quick hover-maptip on ALL parcels?).

If you are going to the devsummit, go to the advanced Silverlight session where I'm planning on showing exactly how to to do something like this (over 200000 high resolution polygons with over 70 attributes in each). If you are not going, keep an eye on the session recordings which should be up there shortly after.

Re: Working With Parcels

BrianGustafson — Fri, 25 Feb 2011 12:31:56 GMT

I am going to be at the devsummit so I will make sure to go to the advanced silverlight session. I have this working similar to how you recommended but when I get to around 100,000 parcels I start having issues with performance so I will be interested in how you get 200,000 polygons loaded.

Thanks

Re: Working With Parcels

DanielWalton — Fri, 25 Feb 2011 15:12:36 GMT

I have a 'piggyback' question. I would like to use Dynamic Map layers to visualize parcels, but I need to perform web editing on them. Is it possible to use IdentifyTask on the map service and hook up the results to an Editor? Or is there a better way to do it?