"SmartNavigation"苗条版ClientNavigation增肥

    原来做的ClientNavigation没有注意只支持保存和恢复页面的scrollTop，今天发现有个应用还需要保存一下scrollLeft，于是就把ClientNavigation增了点肥，支持scrollLeft的save/load了。放在这里算是对SmartNavigation系列文章的update吧。

using System;
using System.Collections;
using System.ComponentModel;
using System.Drawing;
using System.Text;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;

namespace Birdshome.Web.WebControls
{
    /**//// <summary>
    /// Summary description for ClientNavigation.
    /// </summary>
    [DefaultProperty("Text")]
    [ToolboxData("<{0}:ClientNavigation runat=server></{0}:ClientNavigation>")]
    public class ClientNavigation : WebControl, INamingContainer, IPostBackDataHandler
    {
        public ClientNavigation() : base() {}

        Properties#region Properties
        public int PositionTop
        {
            get
            {
                object obj = ViewState["PositionTop"];
                return obj == null ? 0 : (int)obj;
            }
            set
            {
                ViewState["PositionTop"] = value;
            }
        }

        public int PositionLeft
        {
            get
            {
                object obj = ViewState["PositionLeft"];
                return obj == null ? 0 : (int)obj;
            }
            set
            {
                ViewState["PositionLeft"] = value;
            }
        }
        #endregion

        protected override void Render(HtmlTextWriter writer)
        {
            this.RegisterClientScript();
            writer.AddAttribute(HtmlTextWriterAttribute.Type, "hidden");
            writer.AddAttribute(HtmlTextWriterAttribute.Id, this.ClientID);
            writer.AddAttribute(HtmlTextWriterAttribute.Name, this.ClientID);
            writer.AddAttribute(HtmlTextWriterAttribute.Value,
                string.Format("{0}:{1}", this.PositionTop,this.PositionLeft));
            writer.RenderBeginTag(HtmlTextWriterTag.Input);
            writer.RenderEndTag();
        }

        Client Script#region Client Script
        private void RegisterClientScript()
        {
            const string REGISTER_KEY = "__ClientNavigate586787__";
            string strScript = @"
            <script language=""javascript"">
            window.attachEvent('onload', CLN_ClientNavigation);
            function CLN_ClientNavigation()
            {{
                var scrollTop = {0};
                var scrollLeft = {1};
                var scrollCount = 0;
                do
                {{
                    scrollCount ++;
                    window.scrollTo(scrollLeft, scrollTop);
                }}
                while(document.body.scrollTop < scrollTop && scrollCount < 10 );
            }}
            document.body.onscroll = function()
            {{
                var body = document.body;
                document.all.{2}.value = body.scrollTop + ':' + body.scrollLeft;
            }}
            </script>";
            if ( !this.Page.IsStartupScriptRegistered(REGISTER_KEY) )
            {
                strScript = String.Format(strScript, this.PositionTop, this.PositionLeft, this.ClientID);
                this.Page.RegisterStartupScript(REGISTER_KEY, strScript);
            }
        }
        #endregion

        IPostBackDataHandler interface#region IPostBackDataHandler interface
        public void RaisePostDataChangedEvent()
        {
            // TODO:  Add ClientNavigation.RaisePostDataChangedEvent implementation
        }

        public bool LoadPostData(string postDataKey, NameValueCollection postCollection)
        {
            bool modify = false;
            string postData = postCollection[postDataKey];
            if ( !StringHelper.IsEmpty(postData) )
            {
                string [] topleft = postData.Split(new char [] {':'});
                int iPositionTop = int.Parse(topleft[0]);
                int iPostionLeft = int.Parse(topleft[1]);
                if ( iPositionTop != this.PositionTop )
                {
                    this.PositionTop = iPositionTop;
                    modify |= true;
                }
                if ( iPostionLeft != this.PositionLeft )
                {
                    this.PositionLeft = iPostionLeft;
                    modify |= true;
                }
            }
            return modify;
        }
        #endregion
    }
}

    价格公道，童叟无欺，欢迎使用。