从 webmethod 获取会话值会出错

Question

我已经在 webmethod 中设置了当前页面的会话值，我正在尝试获取这些会话值并将它们设置为 javascript 中的变量。
在我的 webmethod 中，这是设置会话值的代码：

HttpContext.Current.Session.Add("benchmark", ds.Tables(0).Rows(0)("bm"))

它有效并且 ds.Tables(0).Rows(0)("bm") 给出 2。以下是我的脚本，它无法获取会话值并将值设为 0。

var bm='';

我的完整 javscript 是：

function ddlpf_SelectedIndexChanged(selectedItemValue)
{
   btn_enable(false);
   var i;
   var userid='<%=Session("userid").toString %>';
   if(ddlpf.selectedIndex > 0)
   {                  
   PageMethods.setpfdetails2(ddlpf.options[ddlpf.selectedIndex].value, userid,onSuc,onErr);
   function onSuc(res){'<%=Session("benchmark")="' + res + '" %>';}
   function onErr(){}
   var bm='<%=Session("benchmark").toString %>';
   var ses='<%=Session("hcur").toString %>';          
   }
alert(bm);
}

我的完整网络方法是：

<WebMethod(EnableSession:=True)> _
<ScriptMethod()> _
   Public Shared Function setpfdetails2(ByVal pfid As String, ByVal uid As String) As String
    Dim da As New dataaccess, para(2) As Object, ds As New DataSet
    Dim strtemp() As String = {"hcur", "mtm", "amtdis", "ratedis", "rd", "dtformat", "day1type", "benchmark", "covmtm", "dtsep", "impset"}
    Try
        For Each strt As String In strtemp
            If HttpContext.Current.Session.Item(strt) IsNot Nothing Then HttpContext.Current.Session.Remove(strt)
        Next
    Catch ex As Exception
    End Try
    custrefdetails1(pfid, uid)
    Try
        para(0) = "SPADD" : para(1) = uid : para(2) = pfid
        ds = da.retds1("select_portfolio", conn, para)
        If ds.Tables(0).Rows.Count > 0 Then
            HttpContext.Current.Session.Add("hcur", ds.Tables(0).Rows(0)("hcur"))
            HttpContext.Current.Session.Add("mtm", ds.Tables(0).Rows(0)("mtm"))
            HttpContext.Current.Session.Add("amtdis", ds.Tables(0).Rows(0)("amtdis"))
            HttpContext.Current.Session.Add("ratedis", ds.Tables(0).Rows(0)("ratedis"))
            HttpContext.Current.Session.Add("rd", ds.Tables(0).Rows(0)("rd"))
            HttpContext.Current.Session.Add("dtformat", ds.Tables(0).Rows(0)("dtformat"))
            HttpContext.Current.Session.Add("day1type", ds.Tables(0).Rows(0)("day1"))
            HttpContext.Current.Session.Add("benchmark", ds.Tables(0).Rows(0)("bm"))
            HttpContext.Current.Session.Add("covmtm", ds.Tables(0).Rows(0)("covmtm"))
            HttpContext.Current.Session.Add("covcancel", ds.Tables(0).Rows(0)("cover"))
            HttpContext.Current.Session.Add("mtmamtsel", ds.Tables(0).Rows(0)("mtmbx"))
            HttpContext.Current.Session.Add("dtsep", ds.Tables(0).Rows(0)("sep"))
            HttpContext.Current.Session.Add("impset", ds.Tables(0).Rows(0)("importset"))
        End If
        HttpContext.Current.Session.Add("datasheettype", ds.Tables(1).Rows(0)(0))
    Catch ex As Exception
    Finally
        ds = Nothing : da = Nothing
    End Try
    Return HttpContext.Current.Session.Item("benchmark")
End Function

Answer 1

而不是会话变量，将其设置为隐藏字段

PageMethods.setpfdetails2(ddlpf.options[ddlpf.selectedIndex].value, userid,onSuc,onErr);
function onSuc(res)
{
   hbm.value=res;
}