I am trying to post values from an AjaxToolKit ComboBox using ASP.NET 4.0. Here

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Editorial Team

Asked: June 10, 20262026-06-10T05:29:27+00:00 2026-06-10T05:29:27+00:00

I am trying to post values from an AjaxToolKit ComboBox using ASP.NET 4.0. Here

0

I am trying to post values from an AjaxToolKit ComboBox using ASP.NET 4.0.

Here is my code:

WebForm1

HTML

<body>
    <ajaxToolkit:ToolkitScriptManager ID="ToolkitScriptManager1" runat="server">
    </ajaxToolkit:ToolkitScriptManager>
    <div>
        <ajaxToolkit:ComboBox ID="ComboBox1" runat="server">
        </ajaxToolkit:ComboBox>
        <asp:Button ID="Button1" runat="server" Text="Button" UseSubmitBehavior="true" PostBackUrl="~/WebForm2.aspx" />
    </div>
</body>

C#

protected void Page_Load(object sender, EventArgs e)
{
    for (int i = 0; i < 5; i++)
    {
        ListItem tmpListItem = new ListItem("Item " + i.ToString());
        tmpListItem.Value = "Item " + i.ToString();
        ComboBox1.Items.Add(tmpListItem);
    }
}

WebForm2

C#

protected void Page_Load(object sender, EventArgs e)
{
    HttpContext tmpHttpContext = HttpContext.Current;
    string cmboBoxValue = tmpHttpContext.Request["ComboBox1"];
}

All I get for cmboBoxValue is null.

I am so frusterated because I know this must be simple. I am sure I have done this 100* in the past.

I looked here

How to submit http form using C#

but that did not help. It has to be submitted with the asp:Button.

Hopefully this is enough information for you to provide a response.

Thank you for your time.