Graph will not dipsplay with custom List! need help

[krb875]

my class is inheriting Window, altho I have tried it with usercontrol as well.  when I make a list of doubles and add it to the series and then to the item source everything works perfectly.  When I make a list of XYMeasure (stole from the example).  The code will not display the graph and I get a null pointer exception when I call show dialog.  code is below:  thanks!

 

double Scale = 20;

this.m_Report.chart1.ItemsSource = null;this.m_Report.chart1.AxisX.ScaleUnit = 1 / Scale;

double location = -40;for (int k = 0; k < value.Length; k++)

{

ChartFX.WPF.SeriesAttributes series = new ChartFX.WPF.SeriesAttributes();

List<ProcessDataSummary.XYMeasure> dataPts = new List<ProcessDataSummary.XYMeasure>();for (int i = 0; i < value[k].Length; i++)

{

dataPts.Add(new ProcessDataSummary.XYMeasure(location, value[k]));

location += Scale;

}

series.ItemsSource = dataPts;

this.m_Report.chart1.Series.Add(series);

}

 

this.m_Report.showDialog();

 

here is a copy of XYMeasure

namespace ProcessDataSummary

{

public class XYMeasure

{

private double m_x;

private double m_y;public XYMeasure(double x, double y)

{

m_x = x;

m_y = y;

}

public double X

{

get { return m_x; }

}

public double Y

{

get { return m_y; }

}

}

 

}