在asp.net中的dropdownlist值中添加数字

Question

我想在下拉列表的选定值中添加值，因为我想在下拉列表的选定值之前选择一条记录。请帮忙。

 Protected Sub ddldomicile_SelectedIndexChanged(sender As Object, e As EventArgs) Handles ddldomicile.SelectedIndexChanged
    sb_loadstate_Rank()
End Sub

Private Sub sb_loadstate_Rank()
    Dim connstring As String = ConfigurationManager.ConnectionStrings("dbcon").ConnectionString
    Dim str As String = "select state_rank + Rand(state_rank) as Rank from  Rank_Master where AIEEE_Rank = '" + ddl_Rank.SelectedItem.Value() + "'"
    con = New SqlConnection(connstring)
    cmd = New SqlCommand(str, con)
    con.Open()
    'Dim dt As New DataTable
    'Dim da As New SqlDataAdapter(cmd)
    'da.Fill(dt)
    drs = cmd.ExecuteReader
    If drs.HasRows Then
        drs.Read()
        txtstate.Text = drs.Item("Rank")
        drs.Close()
    End If
End Sub