//引入命名空间
using System;
using System.Security.Permissions;
using System.Collections;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;

namespace Samples.AspNet.CS.Controls
{
        // Define a type of child control for the custom HtmlSelect control.
    public class MyOption1
    {
        string _id;
        string _value;
        string _text;

        public string optionid
        {
            get
            { return _id; }
            set
            { _id = value; }
        }

        public string value
        {
            get
            { return _value; }
            set
            { _value = value; }
        }

        public string text
        {
            get
            { return _text; }
            set
            { _text = value; }
        }
    }

       // Define a type of child control for the custom HtmlSelect control.
    public class MyOption2
    {
        string _id;
        string _value;
        string _text;

        public string optionid
        {
            get
            { return _id; }
            set
            { _id = value; }
        }

        public string value
        {
            get
            { return _value; }
            set
            { _value = value; }
        }

        public string text
        {
            get
            { return _text; }
            set
            { _text = value; }
        }
    }

    // Define a custom HtmlSelectBuilder control.
    public class MyHtmlSelectBuilder : HtmlSelectBuilder
    {
        [AspNetHostingPermission(SecurityAction.Demand, Level = AspNetHostingPermissionLevel.Minimal)]
        public override Type GetChildControlType(string tagName, IDictionary attribs)
        {
            // Distinguish between two possible types of child controls.
            if (tagName.ToLower().EndsWith("myoption1"))
            {
                return typeof(MyOption1);
            }
            else if (tagName.ToLower().EndsWith("myoption2"))
            {
                return typeof(MyOption2);
            }
            return null;
        }
    }

    [ControlBuilderAttribute(typeof(MyHtmlSelectBuilder))]
    public class CustomHtmlSelect : HtmlSelect
    {
        
        // Override AddParsedSubObject to treat the two types
        // of child controls differently.
        protected override void AddParsedSubObject(object obj)
        {
            string _outputtext;
            if (obj is MyOption1)
            {
                _outputtext = "option group 1: " + ((MyOption1)obj).text;
                ListItem li = new ListItem(_outputtext, ((MyOption1)obj).value);
                base.Items.Add(li);
            }
            if (obj is MyOption2)
            {
                _outputtext = "option group 2: " + ((MyOption2)obj).text;
                ListItem li = new ListItem(_outputtext, ((MyOption2)obj).value);
                base.Items.Add(li);
            }
        }
    }
}