Creating nested ServerControl in asp.net (C#)?

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C#

ASP.NET

server-control

I wanna create a server control like the following :

<%@ Register Assembly="MdsAccordionMenu" Namespace="MdsAccordionMenu" TagPrefix="cc1" %>
    <cc1:MdsAccordionMenu ID="MdsAccordionMenu1"  runat="server">
    	<MdsAccordionMenuItem Title="Some Title">
    		<MdsAccordionMenuItem Text="some text" Link="http://" IconUrl="image.png" />
    		<MdsAccordionMenuItem Text="some text" Link="http://" IconUrl="image.png" />
    		<MdsAccordionMenuItem Text="some text" Link="http://" IconUrl="image.png" />
    		<MdsAccordionMenuItem Text="some text" Link="http://" IconUrl="image.png" />
    	</MdsAccordionMenuItem>
    </cc1:MdsAccordionMenu> 

I written the following c# code , but it doesn't work :
MdsAccordionMenu.cs :

namespace MdsAccordionMenu
    {
    	[ToolboxData("<{0}:MdsAccordionMenu  runat="server"></{0}:MdsAccordionMenu>")]
    	[ParseChildren(true, "MdsAccordionMenuItems")]
    	[DefaultProperty("MdsAccordionMenuItems")]
    	[Serializable]
    	public class MdsAccordionMenu : WebControl
    	{
    		[Description("سرعت نمایش انیمیشن")]
    		[DefaultValue(500)]
    		public int AnimationSpeed { get; set; }
    
    		[Browsable(false), PersistenceMode(PersistenceMode.InnerProperty)]
    		public List<MdsAccordionMenuItem> MdsAccordionMenuItems { get; set; }
    	}
    }

MdsAccordionMenuItem.cs :

namespace MdsAccordionMenu
    {
    	//[TypeConverter(typeof(ExpandableObjectConverter))]
    	[ParseChildren(true, "MdsAccordionItems")]
    	[DefaultProperty("Title")]
    	[Serializable]
    	public class MdsAccordionMenuItem
    	{
    		[Description("تیتر منو")]
    		[DefaultValue("Title")]
    		[NotifyParentProperty(true)]
    		public string Title { get; set; }
    
    		[Browsable(false), PersistenceMode(PersistenceMode.InnerProperty)]
    		[NotifyParentProperty(true)]
    		public List<MdsAccordionItem> MdsAccordionItems { get; set; }
    	}
    }

MdsAccordionItem .cs:

namespace MdsAccordionMenu
    {
        [Serializable]
        public class MdsAccordionItem : INamingContainer
        {
            [NotifyParentProperty(true)]
            [Description("متن")]
            public string Text { get; set; }
    
            [NotifyParentProperty(true)]
            [Description("آدرس لینک منو")]
            public string Link { get; set; }
    
            [NotifyParentProperty(true)]
            [Description("آدرس آیکون")]
            public string ImageUrl { get; set; }
        }
    }

How can I do it?
Could you please guide me ?
Thanks