Questions

I am trying to add a “LineArrowAnnotation” using a composite annotation.
When I run my code (see below) I get an exception (also below).
When I put “AnnotationCoordinateMode” in AnnotationCoordinateMode.Absolute,
it will show the LineArrowAnnotation, but on the wrong place.

When I run my code I get the following exception:

‘NaN’ is not a valid value for property ‘Y1’.

And this is the stack trace:

   at System.Windows.DependencyObject.SetValueCommon(DependencyProperty dp, Object value, PropertyMetadata metadata, Boolean coerceWithDeferredReference, Boolean coerceWithCurrentValue, OperationType operationType, Boolean isInternal)
   at System.Windows.DependencyObject.SetValue(DependencyProperty dp, Object value)
   at SciChart.Charting.Visuals.Annotations.LineArrowAnnotation.c4fae01a1bd9d8777f0acbea006c37ddd(AnnotationCoordinates cb7eea21dddaf59b654790a03f7fecf82, LineArrowAnnotation c7816e538855bcbae71ae0f6efa624460)
   at SciChart.Charting.Visuals.Annotations.LineArrowAnnotation.ca698bc0a82170c849e74a3955c194cda.PlaceAnnotation(AnnotationCoordinates coordinates)
   at SciChart.Charting.Visuals.Annotations.AnnotationBase.PlaceAnnotation(AnnotationCoordinates coordinates)
   at SciChart.Charting.Visuals.Annotations.AnnotationBase.MakeVisible(AnnotationCoordinates coordinates)
   at SciChart.Charting.Visuals.Annotations.AnnotationBase.Update(ICoordinateCalculator`1 xCoordinateCalculator, ICoordinateCalculator`1 yCoordinateCalculator)
   at SciChart.Charting.Visuals.Annotations.CompositeAnnotation.Update(ICoordinateCalculator`1 xCoordinateCalculator, ICoordinateCalculator`1 yCoordinateCalculator)
   at SciChart.Charting.Visuals.Annotations.AnnotationBase.TryUpdate(ICoordinateCalculator`1 xCalc, ICoordinateCalculator`1 yCalc)
   at SciChart.Charting.Visuals.Annotations.AnnotationBase.Refresh()
   at SciChart.Charting.Visuals.Annotations.AnnotationBase.ccc682ea04b7d185ec619d8e3262c6d9b()
   at SciChart.Charting.Visuals.Annotations.AnnotationBase.OnAnnotationLoaded(Object sender, RoutedEventArgs e)
   at System.Windows.RoutedEventHandlerInfo.InvokeHandler(Object target, RoutedEventArgs routedEventArgs)
   at System.Windows.EventRoute.InvokeHandlersImpl(Object source, RoutedEventArgs args, Boolean reRaised)
   at System.Windows.UIElement.RaiseEventImpl(DependencyObject sender, RoutedEventArgs args)
   at System.Windows.UIElement.RaiseEvent(RoutedEventArgs e)
   at System.Windows.BroadcastEventHelper.BroadcastEvent(DependencyObject root, RoutedEvent routedEvent)
   at System.Windows.BroadcastEventHelper.BroadcastLoadedEvent(Object root)
   at MS.Internal.LoadedOrUnloadedOperation.DoWork()
   at System.Windows.Media.MediaContext.FireLoadedPendingCallbacks()
   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, Int32 numArgs)
   at System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Int32 numArgs, Delegate catchHandler)

This is the code I use to draw the “LineArrowAnnotation”:

var line = new LineArrowAnnotation
{
     X1 = (double)annotation.MeasureFrom,
     X2 = (double)annotation.MeasureTo,
     Y1 = 0.9d,
     Y2 = 0.9d,
     Padding = new Thickness(0, 20, 0, 20),
     HeadLength = 4,
     HeadWidth = 6,
     //ToolTip = annotation.Tooltip,
     SnapsToDevicePixels = true,
     //CoordinateMode = AnnotationCoordinateMode.Absolute,
     CoordinateMode = AnnotationCoordinateMode.RelativeY,
     Stroke = new SolidColorBrush(color),
     StrokeDashArray = new DoubleCollection { 2, 2 },
     Tag = annotation,
};
Annotations.Add(line);

Hello,

I am trying to create a XABCD pattern annotation. Currently, I am able to create the XA, AB, BC, CD legs using LineAnnotation then add the two remaining XB and BD lines programmatically. However, when creating the LineAnnotations, I am not getting the real-time feedback between the 1st and 2nd clicks. I have full source code but from what I can see, all SciChart annotations are at most, limited to 2 clicks. I’ve read through the Fibonacci composite annotations which are close to what I’m trying to achieve but only allow interaction by 2 clicks since they’re based on BoxAnnotation.

I am currently using full MVVM with a custom derived class from AnnotationCreationModifier per this article: Editing annotations and keeping track of them in an mvvm application combined with the Multi-Pane Stock Chart example. For the PatternAnnotationViewModel, I am using dependency properties for X, A, B, C, D so they are bindable if needed.

Huge thanks in advance,
Jason

Psuedo code
1st click
Place point X portion of XA LineAnnotation, begin visual feedback for point A
2nd click
Place point A
Set beginning of AB to A, begin visual feedback for point B
3rd click
Place point B
Set beginning of BC, begin visual feedback for point C
Draw XB LineAnnotation
PolygonFill XAB region
4th click
Place point C
Set beginning of CD, begin visual feedback for point D
5th click
Place point D
Draw BD LineAnnotation
PolygonFill BCD region