how to create multi line chart with single datatable in vb.net - sql-server

Question

I am working on vb.net application where i have to create a multi line chart. The table coming from the database using storing procedure is:-
TagName On Off Trip
P1 0 0 1
P2 0 1 1
P3 0 1 0
Q1 0 1 0
Q2 1 0 1
Q3 2 2 2
W1 4 2 1
W2 2 0 1
W3 1 1 0
W4 0 1 1
W5 2 1 1
And the code in vb.net i used to bind the chart named "chTrend" is:-
ds = ObjTags.GetTrendData()
If (ds.Tables(0).Rows.Count > 0) Then
dt = ds.Tables(0)
chTrend.DataSource = dt
chTrend.Series(0).XValueMember = "TagName"
chTrend.Series(0).YValueMembers = "On"
chTrend.Series(1).XValueMember = "TagName"
chTrend.Series(1).YValueMembers = "Off"
chTrend.Series(1).XValueMember = "TagName"
chTrend.Series(1).YValueMembers = "Trip"
For i = 0 To 2
chTrend.Series(i).ChartType = SeriesChartType.Line
chTrend.Series(i).IsVisibleInLegend = True
chTrend.Series(i).IsValueShownAsLabel = True
chTrend.Series(i).ToolTip = "Data Point Y Value #VALY{G}"
chTrend.Series(i).BorderWidth = 3
Next
End If
When i run the program a Error is coming as following
"Index was out of range. Must be non-negative and less than the size of the collection.Parameter name: index"
At the position
chTrend.Series(0).XValueMember = "TagName"
how to solve this?

Answer 1

Assuming that your DataTable only has the four DataColumns {TagName, On. Off. Trip}, then replace everything in your shown code below the line:
chTrend.DataSource = dt
with this.
chTrend.Series.Clear() ' clears any existing series
Dim s As Series
For columnIndex As Int32 = 1 To dt.Columns.Count - 1
Dim name As String = dt.Columns(columnIndex).ColumnName
s = chTrend.Series.Add(name)
s.XValueMember = dt.Columns(0).ColumnName
s.YValueMembers = name
s.ChartType = SeriesChartType.Line
s.IsVisibleInLegend = True
s.IsValueShownAsLabel = True
s.ToolTip = "Data Point Y Value #VALY{G}"
s.BorderWidth = 3
Next
chTrend.DataBind() ' loads the data from dt to the chart
The Chart databinding is a not a binding in the normal sense of binding. You need to tell the chart to copy the data from the source so that it has something to plot. That is what the DataBind method does.