System.Web.HttpException: 此页的状态信息无效，可能已损坏[挑战高手]

Question

Global.asax
void Application_Start(object sender, EventArgs e)
    {
        System.IO.DirectoryInfo dir = new System.IO.DirectoryInfo(this.Server.MapPath("~/App_Data/ViewState/"));
        if (!dir.Exists)
            dir.Create();
        else
        {
            DateTime nt = DateTime.Now.AddHours(-1);
            foreach (System.IO.FileInfo f in dir.GetFiles())
            {
                if (f.CreationTime < nt)
                    f.Delete();
            }
        }
    }
A.aspx页面是新闻
    #region 解决ViewState过于庞大的问题
    protected override object LoadPageStateFromPersistenceMedium()
    {
        string viewStateID = (string)((Pair)base.LoadPageStateFromPersistenceMedium()).Second;
        string stateStr = (string)Cache[viewStateID];
        if (stateStr == null)
        {
            string fn = Path.Combine(this.Request.PhysicalApplicationPath, @"App_Data/ViewState/" + viewStateID);
            stateStr = File.ReadAllText(fn);
        }
        return new ObjectStateFormatter().Deserialize(stateStr);
    }    protected override void SavePageStateToPersistenceMedium(object state)
    {
        string value = new ObjectStateFormatter().Serialize(state);
        string viewStateID = (DateTime.Now.Ticks + (long)this.GetHashCode()).ToString(); //产生离散的id号码
        string fn = Path.Combine(this.Request.PhysicalApplicationPath, @"App_Data/ViewState/" + viewStateID);
        //ThreadPool.QueueUserWorkItem(File.WriteAllText(fn, value));
        File.WriteAllText(fn, value);
        Cache.Insert(viewStateID, value);
        base.SavePageStateToPersistenceMedium(viewStateID);
    }
    #endregion
B.aspx页面是评论
<script type="text/javascript" language="javascript">             
                            function re(){             
                            var xmlhttp;             
                            try{             
                             xmlhttp=new XMLHttpRequest();             
                             }catch(e){              
                             xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");             
                             }              
                             xmlhttp.open("GET","B.aspx",false);               
                             xmlhttp.send();            
                             var str = xmlhttp.responseText;                 
                             document.write(str);                 
                             }re();           
                            </script>
发布评论就出现标题所示的错误，请教大家

Answer 1

源错误：string viewStateID = (string)((Pair)base.LoadPageStateFromPersistenceMedium()).Second;