Closing page errors "loadLayersInView"

Question

Hi, Just to summarise, we are using the v3.0 API for Silverlight (v5). The app does a lot of custom Dispose work to get memory at a minimum as users are constantly opening and closing new maps in the same application instance. When a user closes a tab with and ESRI control on it and the user has done so before the map has finished rendering, a "Error:Object reference not set to an instance of an object" is triggered in : ESRI.ArcGIS.Client.Map.loadLayersInView stack trace : - ESRI.ArcGIS.Client.Map.<>c_DisplayClass22.b_21() - ESRI.ArcGIS.Client.ThrottleTimer - MS.Internal.CoreInvokeHandler.InvokeEventHandler - MS.Internal.JoltHelper.FireEvent Understandably this is because I am flushing ESRI's layer contents on close and a 'Extent = {new map location}' is being triggered right before a tab is closed. Is there a way to suppress this error (or perhaps get a null check added into the next rev of ESRI API)? Omad

DominiqueBroux · Answer

Anyway, I tried running with 3.1 but regretfully this version is more unstable.

Sorry for that.
We are not aware of such issues, so if you had the opportunity to share a repro case that would be very helpful.

Thanks for your help.

DamianBrede · Answer

Sorry I can't reproduce.

If you could share a simple repro case, that would be the best. I don't think the video would help.

Did you try with the version 3.1? It contains some enhancements in loadLayersInView to avoid exceptions in some cases with tiled layers. Not sure it's the same case as yours but it might worth the test.

FYI the 'API Silverlight Download' only talks about 3.0 and not 3.1 :
http://help.arcgis.com/en/webapi/silverlight/index.html

Anyway, I tried running with 3.1 but regretfully this version is more unstable.  When I have some selected features on the map (with overlays to act as tablet friendly markers but these may not be the problem) and zoom in and out quickly using the mouse wheel (so selected features go on and off the screen) then I get a Null Reference that crashes the entire browser ('Unhandled Exception' followed by the browser going completely blank).

😞

I guess I will wait for version 3.2.  Thanks for trying anyway.

DominiqueBroux · Answer

Not that I see how it would help, but should I post a video on youtube of this happening?

Sorry I can't reproduce.

If you could share a simple repro case, that would be the best. I don't think the video would help.

Did you try with the version 3.1? It contains some enhancements in loadLayersInView to avoid exceptions in some cases with tiled layers. Not sure it's the same case as yours but it might worth the test.