Hi,  I’m trying to implement  the  Y-axis  inversion  according to techniques suggested in this forum and  help documentation.  

I’m referring to  Winforms release 2010.2

The technique first suggests to change the sign of values (-1 *):  

no problem, of course.

Then –using IRenderLabel- reverse Y labels too. 

This should be done as follows:

1.      Set the appropriate FormatString property to a unique string value enclosed by "<" and ">" characters.

2.      Create a Hashtable with an entry containing that unique string value without the "<" and ">" characters, and an instance of an IRenderLabel implementation.

3.      Set the UltraChart.LabelHash property value to the Hashtable containing the IRenderLabel implementation.

This is my implementation,

1:  added to  the Form where is Ultrachart1

Public Class MyLabelRenderer

    Implements IrenderLabel

    Public Overloads Function ToString(ByVal context As Hashtable) _

      As String Implements IRenderLabel.ToString

        Dim itemLabel As Double = -1 * CDbl(context("REV_VALUE"))

        Return CStr(itemLabel)

    End Function

End Class

2.

I set up a  scatter chart with one chartArea and several layers

       ‘ … code setting up composite chart,  

       ‘ including <DATA_VALUE> default definition …

       ‘ up to

        myChartArea.Axes.Add(axisX)

        myChartArea.Axes.Add(axisY)

       ' +++++++++++++++++++++++++++++++++++++++++++

1      If bzCurv.grand = 4 Then

2          Dim yAxis As AxisItem = myChartArea.Axes(1)

3          yAxis.Labels.ItemFormat = AxisItemLabelFormat.Custom

4          yAxis.Labels.ItemFormatString = "<REV_VALUE:####0.>"

5      End If

6      Dim MyLabelHashTable As New Hashtable()

7      MyLabelHashTable.Add("REV_VALUE", New MyLabelRenderer())

8        Me.UltraChart1.LabelHash = MyLabelHashTable

       ' +++++++++++++++++++++++++++++++++++++++++++

This doesn’t work : the chart is replaced by the red cross

Since I didn’t  find  an example concerning  composite chart axis  I’m asking if you see where I make a mistake

I believe the  class MyLabelRenderer is correct. 

My doubts are about the code lines with line number.

·         this numbered code is placed in a Init.. method called by Form_Load

·         the test in line 1  tells the type of  chart where this inversion is needed

·         the following definitions are referred to the Y axis of myChartArea

·         6,7, 8 ?

Thanks in advance for any help

Best regards,  Marco Brazzelli