UserControl Viewstate loses all values after postback

Question

I have a user control on a page that needs to persist some state in viewstate. Whenever a postback happens the entries in the viewstate get set to null.

Page

<%@ Page Title="" Language="C#" MasterPageFile="~/Main.master" %>
<%@ Register TagPrefix="JR" TagName="JournalRanking" Src="~/Controls/JournalRankRadioButton.ascx" %>
<script runat="server">
</script>

<asp:Content ID="Content3" ContentPlaceHolderID="Content1placeholder" Runat="Server">
    <asp:Panel CssClass="insetBG1" ID="FormView1" runat="server">
        <JR:JournalRanking ID="JournalRanking1" runat="server" ViewStateMode="Inherit" />
    </asp:Panel>
</asp:Content>

User Control

<%@ Control Language="C#" ClassName="JournalRankRadioButton" %>
<script runat="server">    
    public String Test
    {
        get
        {
            if (ViewState["Test"] == null)
            {
                ViewState["Test"] = String.Empty;
            }
            return ViewState["Test"].ToString();
        }
        set
        {
            ViewState["Test"] = value;
        }
    }

public void Page_Load(object sender, EventArgs e)
{
    if (!Page.IsPostBack)
    {
        this.Test = "Test";
    }
}
</script>
<asp:CheckBox runat="server" AutoPostBack="true" />

When I load the page, ViewState["Test"] gets assigned to "Test", but when I check the checkbox, the page does a postback and ViewState["Test"] is null again. What am I missing?

-Update-

So, even though I was setting EnableViewState = true in the page and the control EnableViewState was false in the master page. I had to add

this.Page.Master.EnableViewState = true;

to the Control to get it to work.

Thanks for the help!

Solution

Your code works perfectly here. The only explanation I can think of is that the ViewState is disabled on a parent control. JournalRanking is inside a page which is inside a MasterPage. Check that you don't have EnableViewState=false anywhere because that would prevent you to retrieve the value on the page postback.

Comments

[user467384]

The EnableViewState was false in the master page (though I couldn't find where it was set explicitly). Setting it to true in the Control fixed the issue.