Infragistics Forums

 Hello,

 I have a Line Chart and Series attached from a Datatable. When I have a NULL Value within a series and using

UltraChart1.LineChart.NullHandling = UltraChart.Shared.Styles.NullHandling.DontPlot

 then it happens that the Datapoint before the Null value is not rendered.

 Steps to reproduce:

Imports Infragistics

Public Class Form1

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

        Dim UltraChart1 As New Win.UltraWinChart.UltraChart
        UltraChart1.ChartType = UltraChart.Shared.Styles.ChartType.LineChart


        Dim LineAppearance01 As New UltraChart.Resources.Appearance.LineAppearance

        With LineAppearance01
            .LineStyle.DrawStyle = UltraChart.Shared.Styles.LineDrawStyle.Solid
            .IconAppearance.Icon = UltraChart.Shared.Styles.SymbolIcon.Circle
            .IconAppearance.IconSize = UltraChart.Shared.Styles.SymbolIconSize.Large
            .Thickness = 3
            .IconAppearance.PE.Fill = Color.MidnightBlue
        End With


        UltraChart1.LineChart.LineAppearances.Add(LineAppearance01)

        UltraChart1.LineChart.NullHandling = UltraChart.Shared.Styles.NullHandling.DontPlot

        Dim dt As New DataTable("Data")

        dt.Columns.Add("Col1", GetType(System.Double))
        dt.Columns.Add("Col2", GetType(System.Double))
        dt.Columns.Add("Col3", GetType(System.Double))
        dt.Columns.Add("Col4", GetType(System.Double))
        dt.Columns.Add("Col5", GetType(System.Double))

        Dim dr As DataRow = dt.NewRow

        dr(0) = 8.0
        dr(1) = DBNull.Value
        dr(2) = 15.5
        dr(3) = 12.0
        dr(4) = 11

        dt.Rows.Add(dr)
        UltraChart1.DataSource = dt
        UltraChart1.DataBind()
        Me.Controls.Add(UltraChart1)
    End Sub
End Class

You see on the chart that the first datapoint [dr(0) = 8.0] is not on the chart.

Change 

        dr(0) = 8.0
        dr(1) = DBNull.Value
        dr(2) = 15.5

To

        dr(0) = 8.0
        dr(1) = 15.5
        dr(2) = DBNull.Value

and try again. Then it works as expected

I really need your help as my User do not trust anymore in the Application.

 Thanks

A line chart requires two consecutive non-null values to draw a section of the line. Any single value surrounded by null values will not be plotted. The same would apply if the first value is followed by a null value. You can try using a scatter chart with ConnectWithLines property set to true, or using FillSceneGraph event to cusom draw an icon where a data point should be. It's not a feature of the line chart to draw a single point.

 Hi,

 thanks for your response. 

Excel does exactly what my user expect. It draws a point where the data is. How to submit a feature request ?

Can you provide me with some information how to draw the point on myself ? how do I get the info which point is connected to a line and which point will not be draw ? 

Thanks

PS Im using Version 2008.1 

A feature can be requested here:
http://devcenter.infragistics.com/Protected/RequestFeature.aspx

As for custom drawing the point, there isn't a way to determine if a line is connected to a given point, but you can loop through your data and look for values followed by nulls and draw a Symbol primitive there.

http://help.infragistics.com/Help/NetAdvantage/NET/2008.2/CLR2.0/html/Chart_Modify_Scene_Graph_Using_FillSceneGraph_Event.html

I used the following logic to draw a symbol for each value from the data table

private void ultraChart1_FillSceneGraph(object sender, Infragistics.UltraChart.Shared.Events.FillSceneGraphEventArgs e)
{
  IAdvanceAxis x = (IAdvanceAxis)e.Grid["X"];
  IAdvanceAxis y = (IAdvanceAxis)e.Grid["Y"];
 
  if (x != null && y != null)
  {
    for (int i = Convert.ToInt32(x.Minimum); i < Convert.ToInt32(x.Maximum); i++)
    {
      if (!(myTable.Rows[i][0] is DBNull))
      {
        Symbol s = new Symbol();
        s.icon = SymbolIcon.Circle;
        s.iconSize = SymbolIconSize.Small;
        s.PE.Fill = Color.Green;
        s.point = new Point((int)x.Map(i), (int)y.Map(myTable.Rows[i][0]));
        e.SceneGraph.Add(s);
      }
    }
  }
}

Hi,

when I draw this Symbol no ToolTip's are shown for this symbol.

How can I add the tooltip for these single point ?

Sorry for the delayed response. To add a tooltip to a custom Symbol you need to add the following to your FillSceneGraph event handler:

s.Caps = PCaps.HitTest | PCaps.Tooltip;
s.Layer = e.ChartCore.GetChartLayer();
s.DataPoint = new NumericDataPoint(12345,"label",false);