telerik报告中的会话为空

我将telerik reports与ASP.NET MVC一起使用，并尝试访问会话变量，但它总是返回null。会话在除以下方法之外的任何其他地方都能完美工作

private void Report4_ItemDataBound(object sender, EventArgs e)
        {
            ReportViewModel model = (ReportViewModel)System.Web.HttpContext.Current.Session["ReqColumns"]; // session is null here

        }

        private void Report4_NeedDataSource(object sender, EventArgs e)
        {
            ReportViewModel model = (ReportViewModel)System.Web.HttpContext.Current.Session["ReqColumns"]; // session is null here

        }

---

如果你能帮上忙，试试这个

// Use parameter

private void HDMF_NeedDataSource(object sender, EventArgs e)
{

    string group= string.Empty;
    string sortBy = string.Empty;
    Telerik.Reporting.Processing.Report report = (Telerik.Reporting.Processing.Report)sender;
    var payoutUID = report.Parameters["payoutUID"].Value.ToString();
    // some code here...
}