problem setting FeatureLayer Where property at run time in code behind

Question

Hi - My app includes a feature layer. The app starts with all features in the layer shown. Later, I give the user a chance to restrict the features to a particular set, I do this by resetting the layer's Where property in a method in the code-behind, like this:FeatureLayer siteLayer = Map.Layers["Sites"] as FeatureLayer;
siteLayer.Where = "PROPERTY_ID = 123";

This should cause all but one feature to disappear from the map. But nothing happens, the map appears unchanged.

Seeing http://forums.esri.com/Thread.asp?c=213&f=2455&t=299876 I add another line:siteLayer.Update();

This causes all features in the map to be cleared. Further, If I try to do anything else in this method with the siteLayer reference (like get its extent so I can zoom to it), I now get a null reference exception.

I see from http://forums.arcgis.com/threads/40125-Is-there-a-feature-layer-quot-completed-quot-event that maybe I should wait to interact with the layer again until that event fires. It doesn't explain however why I either get no change in my map, or all my features disappear.

I also see the developer in that second post is doing something like removing and readding the layer. Is that necessary in my case, seems odd?

Ideas?

MC

JerryBiedenbender · Answer

I figured it out, I had a coded domain set up on my layer and it wanted the number value instead of the text value

markcheyne · Answer

jerry - your experience seems to suggest problems with the Where expression? While I was troubleshooting, if I put my Where expression into the layer's XAML, I'd see what I wanted. Maybe confirm in ArcMap that your Where expression works on that layer?

Also, try removing the DisableClientCaching property, and set the layer Mode to "Snapshot"?

JerryBiedenbender · Answer

I am trying to do this same thing and every time I run my map It displays nothing. The code I am using is.FeatureLayer siteLayer = MyMap.Layers["Dispatch"] as FeatureLayer; siteLayer.Where = "Status = Complete"; siteLayer.Update(); My goal is actually to display everything that is not complete so I also triedFeatureLayer siteLayer = MyMap.Layers["Dispatch"] as FeatureLayer; siteLayer.Where = "Status <> Complete"; siteLayer.Update(); Neither of these work. I also tried adding a where clause on the MainPage.xaml This also did not work, It gave me a blank map. Any advice on this? Thanks, Jerry