topic ArcGISDynamicMapServiceLayer VisibleLayers throw exception on visibility changes in .NET Maps SDK Questions https://community.esri.com/t5/net-maps-sdk-questions/arcgisdynamicmapservicelayer-visiblelayers-throw/m-p/759368#M9491 <HTML><HEAD></HEAD><BODY><P>Hello,</P><P></P><P>We are experiencing sporadic un-handled exception that occurs while loading MPK with multiple layers layer approx. 400+ layers.</P><P>During this process we are restoring VisibleLayers by adding or removing id's to be visible or hidden.</P><P>If&nbsp;comment out '#VisibleLayers.Remove(id)' thant this not happen anymore, but we requires it as we want to change layer and it's sub-layers visibility that has&nbsp;to be&nbsp;controlled by user needs.&nbsp;</P><P></P><P>We are running ArcGIS Runtime&nbsp;10.2.7 version.</P><P></P><P>Exception:</P><P>--------------------------------------------------------------------------------------------------------------------------------------</P><P>System.InvalidOperationException: Collection was modified; enumeration operation may not execute. at System.ThrowHelper.ThrowInvalidOperationException(ExceptionResource resource) at System.Collections.Generic.List`1.Enumerator.MoveNextRare() at System.Collections.Generic.List`1.Enumerator.MoveNext() at System.String.Join<T>(String separator, IEnumerable`1 values) at Esri.ArcGISRuntime.Layers.ArcGISDynamicMapServiceLayer.GetImageExportParameters(ImageParameters properties) at Esri.ArcGISRuntime.Layers.ArcGISDynamicMapServiceLayer.GetImageAsync(ImageParameters properties, CancellationToken cancellationToken) at Esri.ArcGISRuntime.Layers.DynamicCallbackHandler.RequestImage(Int32 width, Int32 height, CoreEnvelope2D core_env, CoreSpatialReference s_ref, Single dpi, Double angle, Boolean wrapAround, Boolean hasTimeExtent, Int64 startTime, Int64 endTime) at RuntimeCoreNet.CoreDynamicLayer.&lt;&gt;c__DisplayClass2.&lt;.ctor&gt;b__0(Int32 width, Int32 height, CoreEnvelope2D extent, IntPtr pNativeSpatialReference, Single dpi, Double angle, Boolean wrapAround, Boolean useTime, Int64 startTime, Int64 endTime)</T></P></BODY></HTML> Wed, 31 Aug 2016 21:57:40 GMT AlexanderLitvak 2016-08-31T21:57:40Z ArcGISDynamicMapServiceLayer VisibleLayers throw exception on visibility changes https://community.esri.com/t5/net-maps-sdk-questions/arcgisdynamicmapservicelayer-visiblelayers-throw/m-p/759368#M9491 <HTML><HEAD></HEAD><BODY><P>Hello,</P><P></P><P>We are experiencing sporadic un-handled exception that occurs while loading MPK with multiple layers layer approx. 400+ layers.</P><P>During this process we are restoring VisibleLayers by adding or removing id's to be visible or hidden.</P><P>If&nbsp;comment out '#VisibleLayers.Remove(id)' thant this not happen anymore, but we requires it as we want to change layer and it's sub-layers visibility that has&nbsp;to be&nbsp;controlled by user needs.&nbsp;</P><P></P><P>We are running ArcGIS Runtime&nbsp;10.2.7 version.</P><P></P><P>Exception:</P><P>--------------------------------------------------------------------------------------------------------------------------------------</P><P>System.InvalidOperationException: Collection was modified; enumeration operation may not execute. at System.ThrowHelper.ThrowInvalidOperationException(ExceptionResource resource) at System.Collections.Generic.List`1.Enumerator.MoveNextRare() at System.Collections.Generic.List`1.Enumerator.MoveNext() at System.String.Join<T>(String separator, IEnumerable`1 values) at Esri.ArcGISRuntime.Layers.ArcGISDynamicMapServiceLayer.GetImageExportParameters(ImageParameters properties) at Esri.ArcGISRuntime.Layers.ArcGISDynamicMapServiceLayer.GetImageAsync(ImageParameters properties, CancellationToken cancellationToken) at Esri.ArcGISRuntime.Layers.DynamicCallbackHandler.RequestImage(Int32 width, Int32 height, CoreEnvelope2D core_env, CoreSpatialReference s_ref, Single dpi, Double angle, Boolean wrapAround, Boolean hasTimeExtent, Int64 startTime, Int64 endTime) at RuntimeCoreNet.CoreDynamicLayer.&lt;&gt;c__DisplayClass2.&lt;.ctor&gt;b__0(Int32 width, Int32 height, CoreEnvelope2D extent, IntPtr pNativeSpatialReference, Single dpi, Double angle, Boolean wrapAround, Boolean useTime, Int64 startTime, Int64 endTime)</T></P></BODY></HTML> Wed, 31 Aug 2016 21:57:40 GMT https://community.esri.com/t5/net-maps-sdk-questions/arcgisdynamicmapservicelayer-visiblelayers-throw/m-p/759368#M9491 AlexanderLitvak 2016-08-31T21:57:40Z