In our software, we allow the user to choose from several curves our math package pushes out to our data model. Basically each curve is represented by a series, and we do some automatic axis management to make sure a properly labeled and unit converted / scale axis exists for that curve (this works).
The issue is that when a user removes a curve, and we attempt to remove the associated axes, we get a crash inside of Chart FX. Our CleanAxes function looks like this:
private void CleanAxes () { List<Axis> rem = new List<Axis> (); foreach (Axis axis in _chart.AxesX) { var query = from s in _chart.Series where s.AxisX == axis select s; if (query.Count () <= 0) { rem.Add (axis); } } foreach (Axis axis in rem) { _chart.AxesX.Remove (axis); } rem.Clear (); foreach (Axis axis in _chart.AxesY) { var query = from s in _chart.Series where s.AxisY == axis select s; if (query.Count () <= 0) { rem.Add (axis); } } foreach (Axis axis in rem) { _chart.AxesY.Remove (axis); } }
Basically it goes through the X and Y Axes lists and removes any axis that no longer has any series using it.
When this code is finished running, and the chart tries to draw again, we get the following exception:
Message: Object reference not set to an instance of an object.Stack Trace: at ChartFX.WPF.Internal.PlotAreaCore.a(Axis A_0, IList`1& A_1, Axis A_2, IList`1& A_3) at ChartFX.WPF.Internal.PlotAreaCore.a(PaintMark A_0, AttributesResolver A_1, Boolean A_2, Boolean A_3, Double A_4, Double A_5, PaintSeriesInfo[] A_6) at ChartFX.WPF.Internal.PlotAreaCore.a(AttributesResolver A_0, Double A_1, Double A_2) at ChartFX.WPF.Internal.PlotAreaCore.a(Double A_0, Double A_1, Boolean A_2) at ChartFX.WPF.Internal.PlotAreaCore.b(Double A_0, Double A_1, Boolean A_2) at ChartFX.WPF.Internal.PlotAreaItems.OnRenderSizeChanged(SizeChangedInfo sizeInfo) at System.Windows.ContextLayoutManager.fireSizeChangedEvents() at System.Windows.ContextLayoutManager.UpdateLayout() at System.Windows.ContextLayoutManager.UpdateLayoutCallback(Object arg) at System.Windows.Media.MediaContext.InvokeOnRenderCallback.DoWork() at System.Windows.Media.MediaContext.FireInvokeOnRenderCallbacks() at System.Windows.Media.MediaContext.RenderMessageHandlerCore(Object resizedCompositionTarget) at System.Windows.Media.MediaContext.RenderMessageHandler(Object resizedCompositionTarget) at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Boolean isSingleParameter) at System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Boolean isSingleParameter, Delegate catchHandler)
Is there some safe way to remover axes that I am not aware of?
Another addition question that isn't really crucial right now, but has me curious: When I do Chart.Series.Clear(), why does ChartFX add two default series back to the chart? When I clear the series, I'd really like it to actually be clear.
