未将对象引用设置到对象的实例。
说明: 执行当前 Web 请求期间,出现未处理的异常。请检查堆栈跟踪信息,以了解有关该错误以及代码中导致错误的出处的详细信息。 异常详细信息: System.NullReferenceException: 未将对象引用设置到对象的实例。源错误: 执行当前 Web 请求期间生成了未处理的异常。可以使用下面的异常堆栈跟踪信息确定有关异常原因和发生位置的信息。 堆栈跟踪:
[NullReferenceException: 未将对象引用设置到对象的实例。]
CuteEditor.Impl.b..ctor(Type type, String key) +74
CuteEditor.a.i(HtmlTextWriter A_0) +147
CuteEditor.Editor.Render(HtmlTextWriter writer) +46
System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter) +27
System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter) +99
System.Web.UI.Control.RenderControl(HtmlTextWriter writer) +25
System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children) +134
System.Web.UI.Control.RenderChildren(HtmlTextWriter writer) +19
System.Web.UI.HtmlControls.HtmlForm.RenderChildren(HtmlTextWriter writer) +163
System.Web.UI.HtmlControls.HtmlContainerControl.Render(HtmlTextWriter writer) +32
System.Web.UI.HtmlControls.HtmlForm.Render(HtmlTextWriter output) +51
System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter) +27
System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter) +99
System.Web.UI.HtmlControls.HtmlForm.RenderControl(HtmlTextWriter writer) +40
System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children) +134
System.Web.UI.Control.RenderChildren(HtmlTextWriter writer) +19
System.Web.UI.Page.Render(HtmlTextWriter writer) +29
System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter) +27
System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter) +99
System.Web.UI.Control.RenderControl(HtmlTextWriter writer) +25
System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +1266
--------------------------------------------------------------------------------
版本信息: Microsoft .NET Framework 版本:2.0.50727.4927; ASP.NET 版本:2.0.50727.4927
说明: 执行当前 Web 请求期间,出现未处理的异常。请检查堆栈跟踪信息,以了解有关该错误以及代码中导致错误的出处的详细信息。 异常详细信息: System.NullReferenceException: 未将对象引用设置到对象的实例。源错误: 执行当前 Web 请求期间生成了未处理的异常。可以使用下面的异常堆栈跟踪信息确定有关异常原因和发生位置的信息。 堆栈跟踪:
[NullReferenceException: 未将对象引用设置到对象的实例。]
CuteEditor.Impl.b..ctor(Type type, String key) +74
CuteEditor.a.i(HtmlTextWriter A_0) +147
CuteEditor.Editor.Render(HtmlTextWriter writer) +46
System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter) +27
System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter) +99
System.Web.UI.Control.RenderControl(HtmlTextWriter writer) +25
System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children) +134
System.Web.UI.Control.RenderChildren(HtmlTextWriter writer) +19
System.Web.UI.HtmlControls.HtmlForm.RenderChildren(HtmlTextWriter writer) +163
System.Web.UI.HtmlControls.HtmlContainerControl.Render(HtmlTextWriter writer) +32
System.Web.UI.HtmlControls.HtmlForm.Render(HtmlTextWriter output) +51
System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter) +27
System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter) +99
System.Web.UI.HtmlControls.HtmlForm.RenderControl(HtmlTextWriter writer) +40
System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children) +134
System.Web.UI.Control.RenderChildren(HtmlTextWriter writer) +19
System.Web.UI.Page.Render(HtmlTextWriter writer) +29
System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter) +27
System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter) +99
System.Web.UI.Control.RenderControl(HtmlTextWriter writer) +25
System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +1266
--------------------------------------------------------------------------------
版本信息: Microsoft .NET Framework 版本:2.0.50727.4927; ASP.NET 版本:2.0.50727.4927
-------------------------------------------
无效的引用,引用异常
using System;
using System.Collections;
using System.Configuration;
using System.Data;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;public partial class user_aboutAdd : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
string userName = Convert.ToString(Session["userName"]);
if (userName == "")
{
Response.Redirect("index.aspx");
}
if (!IsPostBack)
{
int id = Convert.ToInt32(DB.SQLReplace(Request.QueryString["id"]));
Maticsoft.BLL.gsclass bll = new Maticsoft.BLL.gsclass();
Maticsoft.Model.gsclass model = bll.GetModel(id); this.Label1.Text = model.classname; this.WE_NewsContent.Text = model.content;
if (Label1.Text == "企业荣誉")
{
Response.Redirect("Editbout1.aspx");
}
} }
protected void btnAdd_Click(object sender, EventArgs e)
{
string strErr = ""; if (this.WE_NewsContent.Text == "")
{
strErr += "请输入内容!\\n";
} if (strErr != "")
{
MessageBox.Show(this, strErr);
return;
} int id = Convert.ToInt32(DB.SQLReplace(Request.QueryString["id"])); string content = this.WE_NewsContent.Text;
Maticsoft.Model.gsclass model = new Maticsoft.Model.gsclass();
model.id = id;
model.content = content; Maticsoft.BLL.gsclass bll = new Maticsoft.BLL.gsclass();
bll.Update(model);
MessageBox.Show(this, "更新成功");
return;
}
}
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="aboutAdd.aspx.cs" Inherits="user_aboutAdd" %>
<%@ Register TagPrefix="CE" Namespace="CuteEditor" Assembly="CuteEditor" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title></title>
<link href="../img/mycss.css" rel="stylesheet" type="text/css" />
<style type="text/css">
.style1
{
width: 234px;
}
</style>
</head>
<body bgcolor="#DEDDDD" text="#333333" link="#333333" vlink="#333333" alink="#333333" leftmargin="0" topmargin="0" marginwidth="0" marginheight="0">
<form id="form1" runat="server">
<table width="98%" border="0" align="center" cellpadding="0" cellspacing="0" bgcolor="#3A76AF">
<tr>
<td height="28"> <span class="style12"><font color="#FFFFFF"> → 欢迎您的网站</font></span><font color="#FFFFFF"><span class="style12">后台管理系统</span></font></td>
<td align="left"> <strong><span class="C02"><font color="#FFFFFF"></font></span></strong></td>
</tr>
</table>
<br>
<hr align="center" width="98%" size="1" noshade>
<table width="98%" border="0" align="center" cellpadding="4" cellspacing="1" bgcolor="#3A76AF">
<tr>
<td height="23" colspan="2"><div align="center" class="style3"><font color="#FFFFFF"><strong>部门信息</strong></font></div></td>
</tr>
<tr bgcolor="#FFFFFF">
<td height="25" class="style1"><div align="right">类别:</div></td>
<td width="75%" height="25"></a>
<asp:Label ID="Label1" runat="server" Text="Label"></asp:Label>
</td>
</tr>
<tr bgcolor="#FFFFFF">
<td height="25" class="style1"><div align="right">内容:</div></td>
<td height="25">
<CE:Editor id="WE_NewsContent" runat="server" AutoConfigure="Simple"
BreakElement="Br" Width="580px" ></CE:Editor></td>
</tr>
<tr bgcolor="#FFFFFF">
<td height="25" class="style1"> </td>
<td height="25">
<asp:Button ID="btnAdd" runat="server" OnClick="btnAdd_Click" Text="· 提交 ·"
Width="70px" />
</td>
</tr>
</table>
</form>
</body>
</html>
这句在session过期/丢失时就会抛异常
if(Session["userName"] != null)
userName = Session["userName"].ToString();