一个圆角Panel，基于四个裁剪的圆角图片，内部用Table布局

 /// <summary>
    /// 需要的数据如下:
    /// 圆角图片,是要用圆角图片的四个角做为 圆角Panel 的四个角. 具有裁剪效果.
    /// 上下图片,是用上下图片横向铺开来连接上两角和下两角.
    /// 左右图片,是用左右图片竖向铺开来连接左两角和右两角.
    /// 半径, 是指 圆角图片所属圆的半径. 也可以是 圆角图片边长的一半.
    /// 背景色.
    /// </summary>
    [ToolboxData("<{0}:MyPanel runat=server></{0}:MyPanel>")]
    public class MyPanel : Panel
    {
        public MyPanel()
        { }

        public void Bind()
        {
            this.ChildControlsCreated = false;
            this.EnsureChildControls();
        }

        public void Bind(string CircleImagUrl, string TopBottomImageUrl, string LeftRightImageUrl)
        {
            this.CircleImageUrl = CircleImagUrl;
            this.TopBottomImageUrl = TopBottomImageUrl;
            this.LeftRightImageUrl = LeftRightImageUrl;

            Bind();
        }

        public void Bind(string CircleImagUrl, string TopBottomImageUrl, string LeftRightImageUrl, int CircleDiaii, Color BackColor)
        {
            this.CircleImageUrl = CircleImagUrl;
            this.TopBottomImageUrl = TopBottomImageUrl;
            this.LeftRightImageUrl = LeftRightImageUrl;
            this.CircleDiaii = CircleDiaii;
            this.BackColor = BackColor;

            Bind();
        }

        /// <summary>
        /// 
        /// </summary>
        /// <param name="CircleImagUrl"></param>
        /// <param name="TopBottomImageUrl"></param>
        /// <param name="LeftRightImageUrl"></param>
        /// <param name="CircleDiaii"></param>
        /// <param name="BackColor"></param>
        [Obsolete("请用后期 Bind 方法")]
        public MyPanel(string CircleImagUrl, string TopBottomImageUrl, string LeftRightImageUrl, int CircleDiaii, Color BackColor)
        {
            this.CircleImageUrl = CircleImagUrl;
            this.TopBottomImageUrl = TopBottomImageUrl;
            this.LeftRightImageUrl = LeftRightImageUrl;
            this.CircleDiaii = CircleDiaii;
            this.BackColor = BackColor;
        }

        public virtual string CircleImageUrl
        {
            get
            {
                return ViewState["CircleImageUrl"].GetString();
            }
            set
            {
                ViewState["CircleImageUrl"] = value;
            }
        }
        public virtual string TopBottomImageUrl
        {
            get
            {
                return ViewState["TopBottomImageUrl"].GetString();
            }
            set
            {
                ViewState["TopBottomImageUrl"] = value;
            }
        }

        public virtual string LeftRightImageUrl
        {
            get
            {
                return ViewState["LeftRightImageUrl"].GetString();
            }
            set
            {
                ViewState["LeftRightImageUrl"] = value;
            }
        }

        public virtual int CircleDiaii
        {
            get
            {
                return ViewState["CircleDiaii"].GetInt();
            }
            set
            {
                ViewState["CircleDiaii"] = value;
            }
        }

        public override void RenderBeginTag(HtmlTextWriter writer)
        {
            System.Drawing.Image map = System.Drawing.Image.FromFile(HttpContext.Current.Server.MapPath(this.CircleImageUrl.GetVirtualPathFull()));

            
            if (this.BackColor.IsEmpty)
            {
                Bitmap m = new Bitmap(map);
                this.BackColor = m.GetPixel(map.Width/2 - 1, map.Height/2 - 1);
            }

            if (this.CircleDiaii == 0)
            {
                this.CircleDiaii = Math.Min(map.Width, map.Height) / 2;
            }

            writer.Write(string.Format(@"<div style=""{5} white-space: nowrap;background-color:{0};{8}"" class=""{7}"">
    <div style=""background: {0} url({3}) repeat-x scroll 0px 0px; white-space: nowrap; 100%;height:{1}px"">
        <label style=""float: left; background: {0} url({2}) no-repeat scroll 0px 0px; {1}px; height: {1}px; font-size: 1px;""></label>
        <label style=""float: right; background: {0} url({2}) no-repeat scroll -{6}px 0px; {1}px; height: {1}px; font-size: 1px;""></label>
    </div>
    <table style="" 100%;height:100%"" cellpadding=""0px"" cellspacing=""0px"">
        <tr>
            <td style="" {1}px; background: {0} url({4}) repeat-y scroll 0px 0px;""></td>
            <td style=""word-wrap: break-word; word-break: break-all;background-color:{0};height:100%;"" valign=""top"">"
                , this.BackColor.ToHexColorString()
                , this.CircleDiaii.ToString()
                , this.CircleImageUrl.GetUrlFull()
                , this.TopBottomImageUrl.GetUrlFull()
                , this.LeftRightImageUrl.GetUrlFull()
                , this.Width.IsEmpty ? "" : "" + this.Width.ToString() + "px;"
                , map.Width - CircleDiaii
                , this.CssClass
                , this.Attributes["style"]
                ));
        
        }

        public override void RenderEndTag(HtmlTextWriter writer)
        {
            System.Drawing.Image map = System.Drawing.Image.FromFile(HttpContext.Current.Server.MapPath(this.CircleImageUrl.GetVirtualPathFull()));

            writer.Write(string.Format(@"</td>
            <td style="" {1}px; background: {0} url({4}) repeat-y scroll -{6}px 0px;"">
            </td>
        </tr>
    </table>
    <div style=""background: {0} url({3}) repeat-x scroll 0px -{6}px; white-space: nowrap; 100%;height:{1}px"">
        <label style=""float: left; background: {0} url({2}) no-repeat scroll 0px -{6}px; {1}px; height: {1}px; font-size: 1px;""></label>
        <label style=""float: right; background: {0} url({2}) no-repeat scroll -{6}px -{6}px; {1}px; height: {1}px; font-size: 1px;""></label>
    </div>
</div>"
                , this.BackColor.ToHexColorString()
                , this.CircleDiaii.ToString()
                , this.CircleImageUrl.GetUrlFull()
                , this.TopBottomImageUrl.GetUrlFull()
                , this.LeftRightImageUrl.GetUrlFull()
                , this.Width.ToString()
                , map.Width - CircleDiaii
                , this.Width.Value - CircleDiaii 

        ));
        }