VB.Net Dropdownlist Value is always 1 - asp.net

Question

I got a Dropdownlist filled from a Database, using the ID from the Database as ValueField but it just doesn't work
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
Dim strConnection As String = "DEMOString"
connection = New OleDbConnection(strConnection)
connection.ConnectionString = strConnection
connection.Open()
Dim dtb As DataTable
Dim strSql As String = "SELECT * FROM Personen"
dtb = New DataTable()
Using dad As New OleDbDataAdapter(strSql, connection)
dad.Fill(dtb)
End Using
dtb.Columns.Add("Fullname", GetType(String), "Vorname + ' ' + Nachname")
ddlName.Items.Clear()
ddlName.DataSource = dtb
ddlName.DataTextField = "Fullname"
ddlName.DataValueField = "sozNr"
ddlName.DataBind()
connection.Close()
End Sub
When I try using ddlName.SelectedItem.Value later i get 1 for every Item.
The Using Code
Protected Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim dateString As String = tbDate.Text
Dim name As String = ddlName.SelectedItem.Text
Dim des As String = tbDescription.Text
MsgBox(ddlName.SelectedItem.Value)

Answer 1

You don't have to DataBind the DropDownList on every postback if viewstate is enabled(default). That will overwrite all changes like the SelectedIndex. Instead put the code in Page_Load in a Not Is PostBack check:
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
If Not Page.IsPostBack Then
Dim strConnection As String = "DEMOString"
connection = New OleDbConnection(strConnection)
connection.ConnectionString = strConnection
connection.Open()
Dim strSql As String = "SELECT * FROM Personen"
Dim dtb As New DataTable()
Using dad As New OleDbDataAdapter(strSql, connection)
dad.Fill(dtb)
End Using
dtb.Columns.Add("Fullname", GetType(String), "Vorname + ' ' + Nachname")
ddlName.DataSource = dtb
ddlName.DataTextField = "Fullname"
ddlName.DataValueField = "sozNr"
ddlName.DataBind()
connection.Close()
End If
End Sub
Side-Note: you should also not reuse the connection. Instead create, initialize and close it in the method where you use it, best by using the Using-statement which also ensures that it get's disposed/closed in case of an error.