可编辑下拉框，ComboBox asp.net控件

好久没更新了，发个有意思的，可编辑dropdownlist 控件，感觉自己写的挺牛的呵呵。跟大家共享下

    public class ComboBox:System.Web.UI.WebControls.CompositeControl
    {

        private TextBox input;
        private DropDownList select;

        public TextBox TextBox {

            get { this.EnsureChildControls(); return input; }
        }

        public DropDownList DropDownList {

            get { this.EnsureChildControls(); return select; }
        }



        protected override void CreateChildControls()
        {
            //base.CreateChildControls();

            this.Controls.Clear();
            input = new TextBox();
            input.ID = "input";

            select = new DropDownList();
            select.ID =  "select";

            this.Controls.Add(select);
            this.Controls.Add(input);
            this.ChildControlsCreated = true;
        }
        protected override void RenderContents(System.Web.UI.HtmlTextWriter writer)
        {
            this.EnsureChildControls();

  //           <select >);
            writer.RenderEndTag();
        
            


        }

    }