I am using a RadCartesianChart with a ChartSeriesProvider to have multiple ScatterLineSeries plotted. I am controlling the X and Y min and max values displayed programmatically.
I am using a timer so I can change the X axis at some frequency I can set. I am testing it, but I intend to update the X min and max more than once a second so the chart shows a live previous 10 seconds. You can see points when they are created, then move through time until they go off the chart once it's more than 10 seconds old.
I am running into two problems.
I have 4 series. Each one is having points added about once a second. I run until I eventually get
'Collection was modified; enumeration operation may not execute.'
The call stack shows
at System.ThrowHelper.ThrowInvalidOperationException(ExceptionResource resource)
at System.Collections.Generic.List`1.Enumerator.MoveNextRare()
at Telerik.Charting.DataPointCollection`1.<System.Collections.Generic.IEnumerable<Telerik.Charting.DataPoint>.GetEnumerator>d__5.MoveNext()
at Telerik.Charting.NumericalAxisModel.PlotNormal(IEnumerable`1 series)
at Telerik.Charting.NumericalAxisModel.PlotCore(AxisUpdateContext context)
at Telerik.Charting.ChartAreaModelWithAxes.PlotAxisAndCombinedStrategy(AxisModel axis, AxisUpdateContext context)
at Telerik.Charting.ChartAreaModelWithAxes.PlotAxesAndCombinedStrategies(SeriesByAxesTuple seriesByAxes)
at Telerik.Charting.ChartAreaModelWithAxes.ArrangeOverride(RadRect rect)
at Telerik.Charting.ChartNode.Arrange(RadRect rect, Boolean shouldRoundLayout)
at Telerik.Charting.ChartAreaModel.Arrange()
at Telerik.Windows.Controls.ChartView.RadChartBase.CallUpdateUI()
at Telerik.Windows.Controls.ChartView.RadChartBase.OnInvalidated()
...
I think the chart is enumerating through the collection to see if it needs to update the axes every time a point is added. I am setting both axes myself as I have said so I'd think it wouldn't have to do that. If my assumption is correct, is there a way to turn this off? Otherwise should I look at locking the collection, or creating a buffer and adding chunks of data at a time? It does happen when there is just one series, and all 4 series.
Sorry to put two questions in here, but they may be related. I am wondering how much I am overloading the chart. Maybe it's not intended to have the axis updated super frequently so it's view/window moves through time.
The other problem relates to the band annotations I am using. They actually don't change, at least not when the chart is moving through time. I am setting vertical bands. The Y axis range only changes when values come in that are too high. But when that happens, the bands still stay the same. Both upper and lower bands' To and From don't change when the chart is moving through time.
''-1' is not a valid value for 'Width'.'
at System.Windows.DependencyObject.SetValueCommon(DependencyProperty dp, Object value, PropertyMetadata metadata, Boolean coerceWithDeferredReference, Boolean coerceWithCurrentValue, OperationType operationType, Boolean isInternal) in System.Windows\DependencyObject.cs:line 812at System.Windows.DependencyObject.SetValue(DependencyProperty dp, Object value) in System.Windows\DependencyObject.cs:line 605
at Telerik.Windows.Controls.ChartView.CartesianPlotBandAnnotation.UpdatePresenters(ChartLayoutContext context)
at Telerik.Windows.Controls.ChartView.ChartAnnotation.Update(ChartLayoutContext context)
at Telerik.Windows.Controls.ChartView.CartesianStrokedAnnotation.UpdateUICore(ChartLayoutContext context)
at Telerik.Windows.Controls.ChartView.PresenterBase.UpdateUI(ChartLayoutContext context)
at Telerik.Windows.Controls.ChartView.RadChartBase.UpdatePresenters(ChartLayoutContext context, List`1 presenters)
at Telerik.Windows.Controls.ChartView.RadChartBase.UpdateUICore(ChartLayoutContext context)
at Telerik.Windows.Controls.ChartView.PresenterBase.UpdateUI(ChartLayoutContext context)
at Telerik.Windows.Controls.ChartView.RadChartBase.CallUpdateUI()
at Telerik.Windows.Controls.ChartView.RadChartBase.OnInvalidated()
at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs) in System.Windows.Threading\ExceptionWrapper.cs:line 59
at System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Int32 numArgs, Delegate catchHandler) in System.Windows.Threading\ExceptionWrapper.cs:line 24
...
The chart bands shouldn't ever have -1 being set as their width. When this exception happens, none of my code is changing the bands. The properties the bands' To and From are bound to aren't changing. I haven't seen this happen when I just comment out the bands in xaml.
1 Answer, 1 is accepted
Rank 1
Iron
There is a Telerik example of a chart where the x axis updates continuously like I am doing. We dug into the code, it uses a RadObservableCollection and suspends then resumes notifications around adding to the collection.
All the testing I have done so far, this has fixed my issues!