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Get null exception in thinkgeo.mapsuite.wpf.dll

#1

Hi Ethan,
Sometimes, when I try to draw a feature on the map, I got the the exception as following screenshot. Do you have any idea about this?

Exception thrown: ‘System.NullReferenceException’ in ThinkGeo.MapSuite.dll
System.Transactions Critical: 0 : Exception thrown: ‘System.NullReferenceException’ in ThinkGeo.MapSuite.Wpf.dll
Exception thrown: ‘System.NullReferenceException’ in ThinkGeo.MapSuite.dll
Exception thrown: ‘System.NullReferenceException’ in ThinkGeo.MapSuite.Wpf.dll
http://msdn.microsoft.com/TraceCodes/System/ActivityTracing/2004/07/Reliability/Exception/UnhandledUnhandled exceptionSMS-UI.exeSystem.NullReferenceException, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089Object reference not set to an instance of an object. at ThinkGeo.MapSuite.Wpf.Tile.DrawException(GeoCanvas geoCanvas, Exception exception)
at ThinkGeo.MapSuite.Wpf.Tile.Draw(GeoCanvas geoCanvas)
at ThinkGeo.MapSuite.Wpf.Tile.hFY=(Object status)
at System.Threading.QueueUserWorkItemCallback.WaitCallback_Context(Object state)
at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
at System.Threading.QueueUserWorkItemCallback.System.Threading.IThreadPoolWorkItem.ExecuteWorkItem()
at System.Threading.ThreadPoolWorkQueue.Dispatch()
at System.Threading._ThreadPoolWaitCallback.PerformWaitCallback()System.NullReferenceException: Object reference not set to an instance of an object.
at ThinkGeo.MapSuite.Wpf.Tile.DrawException(GeoCanvas geoCanvas, Exception exception)
at ThinkGeo.MapSuite.Wpf.Tile.Draw(GeoCanvas geoCanvas)
at ThinkGeo.MapSuite.Wpf.Tile.hFY=(Object status)
at System.Threading.QueueUserWorkItemCallback.WaitCallback_Context(Object state)
at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
at System.Threading.QueueUserWorkItemCallback.System.Threading.IThreadPoolWorkItem.ExecuteWorkItem()
at System.Threading.ThreadPoolWorkQueue.Dispatch()
at System.Threading._ThreadPoolWaitCallback.PerformWaitCallback()
An unhandled exception of type ‘System.NullReferenceException’ occurred in ThinkGeo.MapSuite.Wpf.dll
Object reference not set to an instance of an object.

image.png1766×836 121 KB

Thanks
Min

#2

Hi Min,

If you want to draw a feature on map, you should choose TrackOverlay, but I hadn’t found it in the exception information.

So could you please sent us a simple sample to reproduce it? Our developer can look into it and see where is the problem.

Regards,

Ethan