Needing Help Utilizing Linq with lists vb net - vb.net

Question

I am creating a routine that opens a SQL reader and loads a "Strapping Chart" (this will look up a predefined number that correlates to a specific volume of a vessel). On form load I want to populate the list these numbers will not change. (VolCnt , Volume). I am wanting to retrieve the correlated Volume based on the volumecount.
Here is what I have :
Public HltVolVals As List(Of HLTVolValChart)
Public Class HLTVolValChart
Public Property VCnt As Double
Public Property Volume As Double
Public Sub New(ByVal n_Vcnt As Double, ByVal n_Volume As Double)
Vcnt = n_Vcnt
Volume = n_Volume
End Sub
End Class
Public Sub PopulateHLTVolVals()
Dim sqlstr As String = "SELECT VCnt, Volume FROM Vol_Strap WHERE Vessel = 'HLT' ORDER BY Volume"
Dim CN As New SqlConnection
Dim Reader As SqlClient.SqlDataReader
Dim SQL As New SqlCommand
CN.ConnectionString = Connectionstr
CN.Open()
SQL.Connection = CN
SQL.CommandText = sqlstr
Reader = SQL.ExecuteReader
While Reader.Read
Dim Vol As Double = CDbl(Reader.GetValue(1))
Dim VCnt As Double = CDbl(Reader.GetValue(0))
Dim NewHLTVolValChartItem As List(Of HLTVolValChart) = New List(Of HLTVolValChart)
NewHLTVolValChartItem.Add(New HLTVolValChart(VCnt, Vol))
End While
Reader.Close()
CN.Close()
CN.Dispose()
End Sub
Public Function ListHLTVals(ByVal CurCnt As Double) As Double
Dim QVol = From _HLTVol In HltVolVals
Where _HLTVol.VCnt >= CurCnt
Select _HLTVol.Volume Take 1
Return QVol.First
End Function
The problem that I am having (I think) is while I loop through the records I am not creating multiple values within HLTVolValChart. However, I am not sure of the proper way to accomplish this.
Any help would be greatly appreciated.

Answer 1

Make NewHLTVolValChartItem a class variable. In your loop don't re-initialize the NewHLTVolValChartItem variable. That make a new List every iteration - just remove that part.
Private NewHLTVolValChartItem As New List(Of HLTVolValChart)
Public Sub PopulateHLTVolVals()
Dim sqlstr As String = "SELECT VCnt, Volume FROM Vol_Strap WHERE Vessel = 'HLT' ORDER BY Volume"
Dim CN As New SqlConnection
Dim Reader As SqlClient.SqlDataReader
Dim SQL As New SqlCommand
CN.ConnectionString = Connectionstr
CN.Open()
SQL.Connection = CN
SQL.CommandText = sqlstr
Reader = SQL.ExecuteReader
While Reader.Read
Dim Vol As Double = CDbl(Reader.GetValue(1))
Dim VCnt As Double = CDbl(Reader.GetValue(0))
NewHLTVolValChartItem.Add(New HLTVolValChart(VCnt, Vol))
End While
Reader.Close()
CN.Close()
CN.Dispose()
End Sub