<%@ Control Language="C#" AutoEventWireup="true" 

    CodeBehind="Demo.ascx.cs" 

    Inherits="UmbracoCreateCustomDatatypeWithWrapper.Demo" %>

<asp:DropDownList ID="control" runat="server">

</asp:DropDownList>

using System;

using System.Data;

using System.Web;

using System.Web.UI.WebControls;

using umbraco.cms.businesslogic.datatype;

namespace UmbracoCreateCustomDatatypeWithWrapper

{

    public partial class Demo : 

        System.Web.UI.UserControl,

        umbraco.editorControls.userControlGrapper.IUsercontrolDataEditor  

    {

        [DataEditorSetting("Connection string")]

        public string ConnectionString { get; set; }

        [DataEditorSetting("Select statement")]

        public string SelectStatement { get; set; }

        [DataEditorSetting("Text column")]

        public string TextColumn { get; set; }

        [DataEditorSetting("Value column")]

        public string ValueColumn { get; set; }

        public string umbracoValue;

        protected void Page_Load(object sender, EventArgs e)

        {

            if (Page.IsPostBack)

            {

                //onsave

                value = control.SelectedValue;

            }

            else

            {

                control.DataSource =

                    Microsoft.ApplicationBlocks.Data.SqlHelper.ExecuteReader(

                    ConnectionString,

                    CommandType.Text,

                    SelectStatement);

                control.DataTextField = TextColumn;

                control.DataValueField = ValueColumn;

                control.DataBind();

                control.Items.Insert(0, new ListItem(String.Empty, String.Empty));

                control.SelectedIndex = 0;

                if (value != null)

                    control.SelectedValue = value.ToString();

            }

        }

        public object value

        {

            get

            {

                return umbracoValue;

            }

            set

            {

                umbracoValue = value.ToString();

            }

        }

    }

}