Public Class frmComboDemo
 
    Dim dt As New DataTable
 
    Dim WithEvents cbo As New ComboBox With
        {.Parent = Me, .DropDownStyle = ComboBoxStyle.DropDownList}
 
 
 
    Private Sub frmComboDemo_Load(sender As Object, 
                 e As EventArgs) Handles MyBase.Load
 
        dt.Columns.Add("Stoff", GetType(String))
        dt.Columns.Add("Faktor", GetType(Double))
 
        dt.Rows.Add("Zement", 0.55)
        dt.Rows.Add("Wasser", 1.0)
        dt.Rows.Add("Salz", 0.3)
 
        cbo.DisplayMember = "Stoff"
        cbo.DataSource = dt
 
    End Sub
 
 
    Private Sub cbo_SelectedIndexChanged(sender As Object, _
        e As EventArgs) Handles cbo.SelectedIndexChanged
 
        If cbo.SelectedIndex >= 0 Then
            Me.Text = dt.Rows(cbo.SelectedIndex)("Faktor").ToString
        End If
    End Sub
End Class