绑定方式1：

        private void BindCombox2(ComboBox cb)
        {
            DataTable dt = new Bll.CoolingWater().GetAllCoolingWater();

            foreach (DataRow r in dt.Rows)
            {
                cb.Items.Add(new Coolite.Ext.Web.ListItem(r[1].ToString(),r[0].ToString()));
            }
        }

绑定方式2：

<ext:Store ID="StoreInfo" runat="server" AutoLoad="true"
     OnRefreshData="InitComboBox">
        <Reader>
            <ext:JsonReader ReaderID="COOLING_WATER_ID">
                <Fields>
                    <ext:RecordField Name="COOLING_WATER_ID">
                    </ext:RecordField>
                    <ext:RecordField Name="COOLING_WATER_NAME">
                    </ext:RecordField>
                </Fields>
            </ext:JsonReader>
        </Reader>
</ext:Store>
<ext:ComboBox ID="Cbo" runat="server" AllowBlank="true"
                        StoreID="StoreInfo" ValueField="COOLING_WATER_ID"
DisplayField="COOLING_WATER_NAME" TriggerAction="All" EmptyText="-请选择-" ReadOnly="true" Width="100px">
</ext:ComboBox>

        public void InitComboBox(object sender, StoreRefreshDataEventArgs e)
        {
            Bll.CoolingWater bo = new Bll.CoolingWater();
            StoreInfo.DataSource = bo.GetAllCoolingWater();
            StoreInfo.DataBind();
        }

原文：http://hi.baidu.com/38608338/blog/item/e6c762f5376d19e67709d754.html