Hi,

Thank you for your quick reply. I protected each access to a graph object with the suggested lock and it seems to work better for now on.

There was a thread by graph used for the data refresh, but I used other functions like hitTest on mouse move / mouse click on the graph and these where handled by the main thread of course. So maybe that was the reason,

Best regards,
Joël

Hi Joel,
This can be caused by multithreading - the control is not thread safe so you need to protect the state from being accessed from different threads - for example suppose that the control render at the time when you modify it. In order to synchronize access to the control state you can use the document Lock/Unlock methods:

nChartControl1.document.Lock();

// modify the chart state here if this code is executed from a different thread

nChartControl1.document.Unlock();

Other than that the problem may be related to incorrect data / incorrect feed of data - to check if this is the reason, simply always feed the whole data - if this fixes the problem then it is related to the code that updates the data partially.

Hope this - let us know if you meet any problems.

Best Regards,
Nevron Support Team

Hello,

I'm using sevral Nevron Charts on a Windows form to display stock of coal and here is a representation of when it works:


The images arent really pretty because they contain lots of tests but for the purpose of this explaination it is good enough.
Every once and a while I refresh some of thoses graphs and for every graph refreshed I sometimes have something like that:


Lots of misplaced points around the graph for no apparent reason.

Here is the code I use for refreshing (executed in separate threads, one for each graph):
  If fRangeSeries IsNot Nothing Then
    Dim ptList As List(Of tGraphPoint) = fDataStorage.GetCells(fSubPile, fCurrentPlotVariable, layer, grid, fLastUpdateDate)
    If ptList IsNot Nothing AndAlso ptList.Count > 0 Then fCurrentPointList = ptList

    If ptList IsNot Nothing AndAlso ptList.Count > 0 Then
    fChartControl.SuspendLayout()

    'If its a full refresh, we clear all points before because we might have changed the grid and receive less points as before
    If fLastUpdateDate = DateTime.MinValue Then
     fRangeSeries.Values.Clear()
     fRangeSeries.Y2Values.Clear()
     fRangeSeries.XValues.Clear()
     fRangeSeries.X2Values.Clear()
     fRangeSeries.ZValues.Clear()
     fRangeSeries.Z2Values.Clear()
    End If
    fLastUpdateDate = Now()

    For i As Integer = 0 To ptList.Count - 1
     Dim pt As tGraphPoint = ptList(i)

     'Nevron Y start - Depth (Z axis)
     If fRangeSeries.Values.Count > i Then
      fRangeSeries.Values(i) = pt.Z
     Else
      fRangeSeries.Values.Add(pt.Z)
     End If

     'Nevron Y end
     If fRangeSeries.Y2Values.Count > i Then
      fRangeSeries.Y2Values(i) = pt.Z + CDbl(fDataStorage.CellDimZ.Value)
     Else
      fRangeSeries.Y2Values.Add(pt.Z + CDbl(fDataStorage.CellDimZ.Value))
     End If

     'Nevron X start - Horizontal (X axis)
     If fRangeSeries.XValues.Count > i Then
      fRangeSeries.XValues(i) = pt.X
     Else
      fRangeSeries.XValues.Add(pt.X)
     End If

     'Nevron X end
     If fRangeSeries.X2Values.Count > i Then
      fRangeSeries.X2Values(i) = pt.X + CDbl(fDataStorage.CellDimX.Value) * grid.X
     Else
      fRangeSeries.X2Values.Add(pt.X + CDbl(fDataStorage.CellDimX.Value) * grid.X)
     End If

     'Nevron Z start - Vertical (Y axis)
     If fRangeSeries.ZValues.Count > i Then
      fRangeSeries.ZValues(i) = pt.Y
     Else
      fRangeSeries.ZValues.Add(pt.Y)
     End If

     'Nevron Z end
     If fRangeSeries.Z2Values.Count > i Then
      fRangeSeries.Z2Values(i) = pt.Y + CDbl(fDataStorage.CellDimY.Value) * grid.Y
     Else
      fRangeSeries.Z2Values.Add(pt.Y + CDbl(fDataStorage.CellDimY.Value) * grid.Y)
     End If

     'Quality value (color of the point)
      If fRangeSeries.FillStyles.Count > i Then
      Dim colorFill As NColorFillStyle = fRangeSeries.FillStyles(i)
      If colorFill IsNot Nothing Then colorFill.Color = fDataStorage.GetColorFromValue(fCurrentPlotVariable, pt.Value, pt.NaLimit)
     Else
      fRangeSeries.FillStyles.Add(i, New NColorFillStyle(fDataStorage.GetColorFromValue(fCurrentPlotVariable, pt.Value, pt.NaLimit)))
     End If
    Next

    End If
   End If

   fChartControl.ResumeLayout()
   fChartControl.Refresh()



Here is the type of the diffrent variable used:
Protected fChartControl As NChartControl
Protected fChart As NCartesianChart
Protected fRangeSeries As NRangeSeries

The series is created like this:
  fRangeSeries = New NRangeSeries()
  fRangeSeries.Name = String.Format("nRangeSeries_{0}", fSubPile.ToString())
  fRangeSeries.InflateMargins = False
  fRangeSeries.DataLabelStyle.Visible = False
  fRangeSeries.Legend.Mode = SeriesLegendMode.None
  fRangeSeries.BorderStyle.Width = New NLength(0)
  fRangeSeries.UseXValues = True
  fRangeSeries.UseZValues = True
  fRangeSeries.Shape = BarShape.Bar


Thank you very much for any help provided on this issue.

Best regards,
Joël