How can I disable ViewState for dynamically created controls?

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Page1.aspx.cs" Inherits="Page1" EnableViewState="false" %>
...
<asp:PlaceHolder ID="DropDownPlaceHolder" runat="server" EnableViewState="false" />
<asp:Button ID="Submit" runat="server" OnClick="Submit_OnClick" Text="Click Me!"  EnableViewState="false"/>
...

protected override void OnInit(EventArgs e)
{
    DropDownList dropDown = new DropDownList();
    TextBox textBox = new TextBox();

    textBox.EnableViewState = false;

    dropDown.Items.Add("Apple");
    dropDown.Items.Add("Dell");
    dropDown.Items.Add("HP");

    dropDown.AutoPostBack = true;
    dropDown.EnableViewState = false;

    DropDownPlaceHolder.Controls.Add(dropDown);
    DropDownPlaceHolder.Controls.Add(textBox);

    base.OnInit(e);
}

Public Sub Page_In(ByVal sender As Object, ByVal e As EventArgs) _
 Handles Me.LoadComplete

    Dim ddl As New DropDownList()
    ddl.EnableViewState = False
    ddl.Items.Add("Hello")
    ddl.Items.Add("Stackoverflow")

    phTest.Controls.Add(ddl)

End Sub