ASPX會話狀態空例外,我似乎無法得到一個會話變量就回傳讀取,即使下面的簡單代碼:上回發
Default.apsx:
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs"
Inherits="_Default" %>
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title></title>
</head>
<body>
<form id="form1" runat="server">
<div>
</div>
<asp:Button ID="Button1" runat="server" OnClick="Button1_Click" AutoPostBack="true" Text="Button" />
</form>
</body>
</html>
代碼隱藏:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
public partial class _Default : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
if (IsPostBack)
{
varcheck(Session["MyVar"].ToString());
}
}
protected void varcheck(string checker)
{
System.Diagnostics.Debug.WriteLine(checker);
}
protected void Button1_Click(object sender, EventArgs e)
{
string ret_val = "Return this on postback";
Session["MyVar"] = ret_val;
}
}
我得到:
An exception of type 'System.NullReferenceException' occurred in App_Web_5mcbvlrk.dll but was not handled in user code
Additional information: Object reference not set to an instance of an object.
我缺少的東西?不應該在點擊按鈕時設置Session變量並在Postback上閱讀?它是否需要全局設置?
停止使用會話請 –