进度条的创造与使用

protected void Button1_Click(object sender, EventArgs e)
    {
        ShowLoading("正在搜索...");
    }
    protected void Button2_Click(object sender, EventArgs e)
    {
        RemoveLoading();
    }
 #region 数据加载进度条
    /// <summary> 
    /// 显示页面正在加载中效果 
    /// </summary> 
    public void ShowLoading(string msg)
    {
        StringBuilder s = new StringBuilder();
        s.Append(" <script language=JavaScript type=text/javascript>\n");
        s.Append(" var t_id = setInterval(animate,20);\n");
        s.Append(" var pos=0;var dir=2;var len=0;\n");
        s.Append(" function animate(){\n");
        s.Append(" var elem = document.getElementById('progress');\n");
        s.Append(" if(elem != null) {\n");
        s.Append(" if (pos==0) len += dir;\n");
        s.Append(" if (len>32 || pos>79) pos += dir;\n");
        s.Append(" if (pos>79) len -= dir;\n");
        s.Append(" if (pos>79 && len==0) pos=0;\n");
        s.Append(" elem.style.left = pos;\n");
        s.Append(" elem.style.width = len;\n");
        s.Append(" }}\n");
        s.Append(" function removeLoadMsg() {\n");
        s.Append(" this.clearInterval(t_id);\n");
        s.Append(" var targelem = document.getElementById('loader_container');\n");
        s.Append(" targelem.style.display='none';\n");
        s.Append(" targelem.style.visibility='hidden';\n");
        s.Append(" }\n ");
        s.Append("</script>\n");
        s.Append("<style>");
        s.Append("#loader_container {text-align:center; position:absolute; top:40%; width:100%; left: 0;}\n");
        s.Append("#loader {font-family:Tahoma, Helvetica, sans; font-size:11.5px; color:#000000; background-color:#FFFFFF; padding:10px 0 16px 0; margin:0 auto; display:block; width:130px; border:1px solid #5a667b; text-align:left; z-index:9999;}\n");
        s.Append("#progress {height:5px; font-size:1px; width:1px; position:relative; top:1px; left:0px; background-color:#8894a8;}\n");
        s.Append("#loader_bg {background-color:#e4e7eb; position:relative; top:8px; left:8px; height:7px; width:113px; font-size:1px;}\n");
        s.Append("</style>\n");
        s.Append("<div id=loader_container>\n");
        s.Append("<div id=loader>\n");
        s.Append("<div align=center>" + msg + "</div>\n");
        s.Append("<div id=loader_bg><div id=progress> </div></div>\n");
        s.Append("</div></div>\n ");
        //HttpContext.Current.Response.Write(s.ToString()); 
        HttpContext.Current.Response.Write(s.ToString());
        HttpContext.Current.Response.Flush();

    }



    public void RemoveLoading()
    {
        ClientScript.RegisterClientScriptBlock(typeof(string), "", "<script>removeLoadMsg();</script>");
    }#endregion