Custom Web Controls - Full Code

gistfile1.cs

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Text;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Drawing.Design;
 
namespace CodersDigest.Web.UI.ExtendedControls
{
    [ToolboxData("<{0}:HoverImageButton runat=server></{0}:HoverImageButton>")]
    public class HoverImageButton : ImageButton
    {
        [Bindable(true)]
        [Category("Appearance")]
        [DefaultValue("")]
        [Localizable(true)]
        [UrlProperty(), Editor("System.Web.UI.Design.UrlEditor, System.Design, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a", typeof(UITypeEditor)), Themeable(false)]
        public string ImageHoverUrl
        {
            get
            {
                String s = (String)ViewState["ImageHoverUrl"];
                return ((s == null) ? String.Empty : s);
            }
            set
            {
                ViewState["ImageHoverUrl"] = value;
            }
        }
 
        protected override void OnPreRender(EventArgs e)
        {
            base.OnPreRender(e);
            string resourceName = "ExtendedControls.HoverImageButtonJS.js";
            ClientScriptManager cs = this.Page.ClientScript;
            cs.RegisterClientScriptResource(typeof(CodersDigest.Web.UI.ExtendedControls.HoverImageButton), resourceName);
        }

        protected override void OnInit(EventArgs e)
        {
            base.OnInit(e);
            this.Attributes.Add("onmouseover", "ShowImageHoverButton(this, '" + this.ResolveUrl(ImageHoverUrl) + "')");
            this.Attributes.Add("onmouseout", "ShowImageHoverButton(this, '" + this.ResolveUrl(ImageUrl) + "')");
        }

        protected override void RenderContents(HtmlTextWriter output)
        {
            this.Attributes.Add("onmouseover", "ShowImageHoverButton(this, '" + this.ResolveUrl(ImageHoverUrl) + "')");
            this.Attributes.Add("onmouseout", "ShowImageHoverButton(this, '" + this.ResolveUrl(ImageUrl) + "')");
            output.Write(Text);
        }
    }
}