为什么我有后台给前台的DIV赋值会报这样的异常呢

Question

commlist.InnerHtml “((System.Web.UI.HtmlControls.HtmlContainerControl)(this.commlist))”为 null注：<div runat="server" id="commlist">这里是评论内容</div>这是前台代码
sb.Append("</table>");
           commlist.InnerHtml = sb.ToString();这是后台部分代码

Answer 1

贴一下全部后台代码
这是一个AJAXPRO方法
 [AjaxPro.AjaxMethod]
    public string  GetCommentary()
    {
        SqlConnection conn = new SqlConnection("server=localhost;database=B2CNetShop;uid=sa;pwd=123;");
        StringBuilder sb = new StringBuilder();        DataTable dt = new DataTable();
        dt.Columns.Add("CommentaryId");
        dt.Columns.Add("UsersID");
        dt.Columns.Add("CommentaryTime");
        dt.Columns.Add("GradeInfo");
        dt.Columns.Add("CommentaryInfo");
        dt.Columns.Add("ReCount");
        sb.Append("<table>");
        try
        {
            conn.Open();
            SqlCommand cmd = new SqlCommand("", conn);
            cmd.CommandText = "select * from Commentary";
            SqlDataReader sdr = cmd.ExecuteReader();
            while (sdr.Read())
            {
                DataRow dr=dt.NewRow();
                dr["CommentaryId"] = sdr["CommentaryId"];
                dr["UsersID"] = sdr["UsersID"];
                dr["CommentaryTime"] = sdr["CommentaryTime"];
                dr["GradeInfo"] = sdr["GradeInfo"];
                dr["CommentaryInfo"] = sdr["CommentaryInfo"];
                dr["ReCount"] = sdr["ReCount"];
                dt.Rows.Add(dr);
                
                sb.Append("<tr>");
                sb.Append("<td>" + sdr["CommentaryInfo"].ToString() + "</td>");
                sb.Append("</tr>");
                
                //sb.Append("<li><div class=\"user\"><a href=\"javascript:OpenWindowUser(523)\"><img src='/Style/images/boy.gif' width =\"50\" /></a><a href=\"javascript:OpenWindowUser(523)\"><span class=\"name\">lantian</span></a></div>");
                //sb.Append("<div class=\"vote2\"><ul class='voteItems' id='disShowStart_2171''><li><span class='voteKey'>结帐速度：</span><span class='start'><img src='/Style/Images/Empty.gif' class=start_4 /></span></li><li><span class='voteKey'>产品布局：</span><span class='start'><img src='/Style/Images/Empty.gif' class=start_5 /></span></li><li><span class='voteKey'>产品质量：</span><span class='start'><img src='/Style/Images/Empty.gif' class=start_5 /></span></li><li><span class='voteKey'>服务态度：</span><span class='start'><img src='/Style/Images/Empty.gif' class=start_5 /></span></li></ul></div>");
                //sb.Append("<div class=\"preview\">" + sdr["CommentaryInfo"].ToString() + "</div>");
                //sb.Append("<div class=\"info\"><span><a href=\"javascript: myLightWindow.activateWindow({href: '/ViewCommentary-2171-0-161.html', title: '评论全文',height:480,width:850});\" title=\"评论全文\">(全文)</a></span><span>[" + sdr["CommentaryTime"].ToString() + "]</span><span><a href='javascript:OkToRe(2171)'>发表回应</a>(共有0个回应)</span></div>");
                //sb.Append("<div class=\"responsesPost\" id='SentRe_2171' style=\"display:none;\"><span>回应内容：</span><span id='Err2171' style=\"color:Red;\"></span><textarea id='Re2171' rows=\"5\" cols=\"40\"  style=\"background-image:url('Images/warning.gif'); background-repeat:no-repeat; background-position:right\"></textarea><input name=\"\" type=\"button\" value=\"回应\" class=\"button\" onclick='javascript:DisRe(2171)' /><input name=\"\" type=\"button\" value=\"取消\" class=\"button\" onclick='javascript:NoToRe(2171)' /></div><ul class='responses' id='livalue_2171'></ul></li>");
            }
           sb.Append("</table>");
           commlist.InnerHtml = sb.ToString();
        }
        catch
        { }
        finally
        {
            conn.Close();
        } 
        
        
        return sb.ToString();
    }

Answer 2

建议你在往前台输出的时候看一下 sb的值，commlist.innerhtml=sb.tostring()这句肯定没问题