How to Develop a Simple Vertical Text Scroller Custom Server Control in ASP.NET

using System;
using System.Collections.Generic;
using System.Text;
using System.ComponentModel;
using System.Web.UI.WebControls;
using System.Web.UI;
using System.Web;
using System.Security.Permissions;
using System.Web.UI.Design;
using System.Drawing.Design;

namespace MyTextScroller
{
    /// <summary>
    /// Author Bryian Tan
    /// Text Scroller v1.1 
    /// </summary>
    [
        AspNetHostingPermission(SecurityAction.Demand, Level = AspNetHostingPermissionLevel.Minimal),
        AspNetHostingPermission(SecurityAction.InheritanceDemand, Level = AspNetHostingPermissionLevel.Minimal),
        ParseChildren(true, "innerHTML"),
        DefaultProperty("innerHTML"),
        ToolboxData("<{0}:TextScroller runat=\"server\"> </{0}:TextScroller>")
        
    ]
    public class TextScroller : WebControl, INamingContainer
    {
        #region Public Properties

        //width of the div
        private Unit width = Unit.Pixel(260);
        public override Unit Width
        {
            get { return width; }
            set { EnsureChildControls(); width = value; }
        }

        //height of the div
        private Unit height = Unit.Pixel(160);
        public override Unit Height
        {
            get { return height; }
            set { EnsureChildControls(); height = value; }
        }

        //content
        private string _innerHTML = "Your Content here";

        [   
            Browsable(true), //display this property in designer
            Category("Appearance"),
            DefaultValue("Your Content Here"),
            Description("The Content to Display."), 
            PersistenceMode(PersistenceMode.InnerDefaultProperty)
        ]
        public virtual string innerHTML
        {
            get
            {
                return _innerHTML;
            }
            set
            {
                EnsureChildControls(); 
                _innerHTML = value; 
            }
        }

        #endregion 

        protected override void OnInit(EventArgs e)
        {

            base.OnInit(e);

            //access embedded Resource
            this.Page.ClientScript.RegisterClientScriptInclude(
                        this.GetType(), "TextScroller",
                        Page.ClientScript.GetWebResourceUrl(this.GetType(),
                        "MyTextScroller.TextScroller.js"));

            // create the style sheet control and put it in the document header
            string csslink = @"<link rel='stylesheet' type='text/css' href='" + Page.ClientScript.GetWebResourceUrl(this.GetType(), "MyTextScroller.TextScroller.css") + "' />";
            LiteralControl include = new LiteralControl(csslink);

            this.Page.Header.Controls.Add(include);

        }

        protected override void OnPreRender(EventArgs e)
        {
            base.OnPreRender(e);
        }

        protected override void Render(HtmlTextWriter output)
        {
            EnsureChildControls();

            output.Write(GenerateDiv());
        }

        private string GenerateDiv()
        {
            StringBuilder b = new StringBuilder();
            ClientScriptManager cs = Page.ClientScript;
            Type rsType = this.GetType();

            b.Append("<div style=\"width:");
            b.Append(width.Value);
            b.Append("px;width/**/:");
            b.Append(width.Value + 20);
            b.Append("px !important; height: ");
            b.Append(Height.Value);
            b.Append("px; \" class = \"MS_vmarquee_div\">");
            b.Append("<div id=\"marqueecontainer\" style=\"float:left; width:");
            b.Append(width.Value - 10);
            b.Append("px;width/**/: ");
            b.Append(width.Value - 10);
            b.Append(@"px !important;\width:");
            b.Append(width.Value);
            b.Append(@"px;w\idth:");
            b.Append(width.Value - 10);
            b.Append("px !important; height:");
            b.Append(Height.Value - 5);
            b.Append(@"px; hei\ght:");
            b.Append(Height.Value - 10);
            b.Append("px;\" class=\"MS_marqueecontainer\" onMouseover=\"copyspeed=pausespeed\" onMouseout=\"copyspeed=marqueespeed\">");

            //content
            b.Append("<div id=\"vmarquee\" class=\"MS_vmarquee_content\">");
            b.Append(innerHTML);
            b.Append("</div>"); //vmarquee
            b.Append("</div>"); //marqueecontainer       
            b.Append(" <div class=\"floatright center\">");

            //up button
            b.Append(" <img alt=\"U\" src=\"");
            b.Append(cs.GetWebResourceUrl(rsType, "MyTextScroller.images.nav-arrow-up.gif"));
            b.Append("\" width=\"13\" height=\"13\" border=\"0\" id=\"MS_rollfirst\" ");
            b.Append("onmouseover=\"document.getElementById('MS_rollfirst').src='");
            b.Append(cs.GetWebResourceUrl(rsType, "MyTextScroller.images.nav-arrow-up-hover.gif"));
            b.Append("';pressup();\"");
            b.Append("onmouseout=\"document.getElementById('MS_rollfirst').src='");
            b.Append(cs.GetWebResourceUrl(rsType, "MyTextScroller.images.nav-arrow-up.gif"));
            b.Append("';mouse_out();\">");

            b.Append("<br>");

            //down button
            b.Append("<img  alt=\"D\" src=\"");
            b.Append(cs.GetWebResourceUrl(rsType, "MyTextScroller.images.nav-arrow-down.gif"));
            b.Append("\" width=\"13\" height=\"13\" border=\"0\" id=\"MS_rollfirst2\" ");
            b.Append("onmouseover=\"document.getElementById('MS_rollfirst2').src='");
            b.Append(cs.GetWebResourceUrl(rsType, "MyTextScroller.images.nav-arrow-down-hover.gif"));
            b.Append("';pressdown();\"");
            b.Append(" onmouseout=\"document.getElementById('MS_rollfirst2').src='");
            b.Append(cs.GetWebResourceUrl(rsType, "MyTextScroller.images.nav-arrow-down.gif"));
            b.Append("';mouse_out();\">	");

            //hidden field
            b.Append("<input id=\"track\" name=\"MS_track\" type=\"hidden\" value=\"\" />");
            b.Append("</div>"); //floatright

            b.Append("</div>"); //MS_vmarquee_div

            return b.ToString();
        }

        protected override void CreateChildControls()
        {
            Controls.Clear();
        }

        protected override void OnLoad(EventArgs e)
        {
            base.OnLoad(e); 
        }    

    }
}