[ToolboxData("<{0}:BigImageButton runat=server></{0}:BigImageButton>")]
    public class BigImageButton : Button
    {
        private string GetDefaultImageUrl()
        {
            return Page.ClientScript.GetWebResourceUrl(GetType(), "myCustomControl.images.BigButton.gif");  //这个图片的类型为嵌入的资源
        }

        protected override void AddAttributesToRender(HtmlTextWriter writer)
        {
            base.AddAttributesToRender(writer);
            writer.AddStyleAttribute(HtmlTextWriterStyle.BorderStyle, "none");
            writer.AddStyleAttribute(HtmlTextWriterStyle.BackgroundImage, String.Format("url({0})", GetDefaultImageUrl()));  //指定背景图片
            writer.AddStyleAttribute(HtmlTextWriterStyle.Width,"85px");
            writer.AddStyleAttribute(HtmlTextWriterStyle.Padding,"0 0 0 0");
            writer.AddStyleAttribute(HtmlTextWriterStyle.Height, "23px");
        }
    }