Multicolumn selected dropdownlist is not showing the dropdown values

<telerik:RadComboBox RenderMode="Lightweight" runat="server" ID="RadComboBox2"  
            MarkFirstMatch="true"  EnableLoadOnDemand="true" AutoPostBack="true" OpenDropDownOnLoad="true"
            HighlightTemplatedItems="true" OnClientItemsRequested="UpdateItemCountField"
            
            OnDataBound="RadComboBox2_DataBound" OnItemDataBound="RadComboBox2_ItemDataBound"
            OnItemsRequested="RadComboBox2_ItemsRequested" DropDownCssClass="exampleRadComboBox">
            <HeaderTemplate>
                <ul>
                    <li class="col1">Name</li>
                    <li class="col2">Date</li>
                    <li class="col3">Gender</li>
                    <li class="col4">Location</li>
                </ul>
            </HeaderTemplate>
            <ItemTemplate>
                
            </ItemTemplate>
            <FooterTemplate>
                A total of
                <asp:Literal runat="server" ID="RadComboItemsCount" />
                items
            </FooterTemplate>
        </telerik:RadComboBox>

protected void Page_Load(object sender, EventArgs e)
        {
            if(!IsPostBack)
            {
                Bind_ComboBox();
            }
        }
protected void RadComboBox2_DataBound(object sender, EventArgs e)
        {
           
            //((Literal)RadComboBox2.Footer.FindControl("RadComboItemsCount")).Text = Convert.ToString(RadComboBox2.Items.Count);
        }

        protected void RadComboBox2_ItemsRequested(object sender, RadComboBoxItemsRequestedEventArgs e)
        {
            
            SqlCommand cmd = new SqlCommand("SELECT * From Sampledb1 where [id]='" + ID + "'", cn);
            SqlDataAdapter da = new SqlDataAdapter(cmd);

            
            RadComboBox2.DataBind();
        }
        protected void RadComboBox2_ItemDataBound(object sender, RadComboBoxItemEventArgs e)
        {
           
            e.Item.Text = ((DataRowView)e.Item.DataItem)["Name"].ToString();
            e.Item.Value = ((DataRowView)e.Item.DataItem)["Id"].ToString();
        }