[NullReferenceException: 未将对象引用设置到对象的实例。] 如何解决，急急急

“/”应用程序中的服务器错误。
--------------------------------------------------------------------------------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。]
   ELOAN365.Tools.DBOperation.GetIDataReader(String sql) +103
   ELOAN365.Tools.Tools.ChickSysInfo(Page page) +102
   ELOAN365._Default.Page_Load(Object sender, EventArgs e) +92
   System.Web.Util.CalliHelper.EventArgFunctionCaller(IntPtr fp, Object o, Object t, EventArgs e) +14
   System.Web.Util.CalliEventHandlerDelegateProxy.Callback(Object sender, EventArgs e) +35
   System.Web.UI.Control.OnLoad(EventArgs e) +99
   System.Web.UI.Control.LoadRecursive() +50
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +627
--------------------------------------------------------------------------------
版本信息: Microsoft .NET Framework 版本:2.0.50727.3643; ASP.NET 版本:2.0.50727.3634 演示地址是:http://net.viphe.net 请高手们指教

解决方案 »

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值可能是空的吧，你可以再出错的地方之前做个if判断
if(xx!=null)
{
........         //里面是你写的代码
}
看他有没有进if里面
断点调试
web.config代码如下
<?xml version="1.0" encoding="utf-8"?><configuration>

    <connectionStrings>
        <add name="Eloan365ConnectionString1" connectionString="Data Source=(local);Initial Catalog=Eloan365;Integrated Security=True; MultipleActiveResultSets=False;Packet Size=4096;Application Name="Microsoft SQL Server Management Studio""
            providerName="System.Data.SqlClient" />
        <add name="Eloan365ConnectionString2" connectionString="Data Source=.;Initial Catalog=Eloan365;Integrated Security=True; MultipleActiveResultSets=False;Packet Size=4096;Application Name="Microsoft SQL Server Management Studio""
            providerName="System.Data.SqlClient" />
        <add name="Eloan365ConnectionString3" connectionString="Data Source=CHIN-B5ADD1A5F9;Initial Catalog=Eloan365;Integrated Security=True;MultipleActiveResultSets=False;Packet Size=4096;Application Name="Microsoft SQL Server Management Studio""
            providerName="System.Data.SqlClient" />
    </connectionStrings>
    <appSettings>
<add key="w116255175211/SQLEXPRESS" value="Data Source=(local);Initial Catalog=Eloan365;User ID=sa;Password=zzidc2012;Max Pool Size=2000" />

<add key="DictionaryFolder" value="bin" />
     </appSettings>
    <system.web>
      <httpHandlers>
        <add verb="POST,GET" path="ajaxpro/*.ashx" type="AjaxPro.AjaxHandlerFactory, AjaxPro.2"/>      </httpHandlers>
      <pages enableEventValidation="true">

      </pages>
      <sessionState mode="InProc" stateConnectionString="tcpip=127.0.0.1:42424" sqlConnectionString="data source=(local);Trusted_Connection=yes"  cookieless="false" timeout="60"/>
      <browserCaps>      tagwriter=System.Web.UI.HtmlTextWriter    </browserCaps>
        
        <compilation debug="true" />
        
        <authentication mode="Windows" />
      <customErrors mode="Off"/>
        
    </system.web>
</configuration>
我就不知道怎么调试了怎么调都是出错误
可能为null 你又要 .  这个对象的都判断下
这下就是
web.config代码如下
<?xml version="1.0" encoding="utf-8"?><configuration>

    <connectionStrings>
        <add name="Eloan365ConnectionString1" connectionString="Data Source=(local);Initial Catalog=Eloan365;Integrated Security=True; MultipleActiveResultSets=False;Packet Size=4096;Application Name="Microsoft SQL Server Management Studio""
            providerName="System.Data.SqlClient" />
        <add name="Eloan365ConnectionString2" connectionString="Data Source=.;Initial Catalog=Eloan365;Integrated Security=True; MultipleActiveResultSets=False;Packet Size=4096;Application Name="Microsoft SQL Server Management Studio""
            providerName="System.Data.SqlClient" />
        <add name="Eloan365ConnectionString3" connectionString="Data Source=CHIN-B5ADD1A5F9;Initial Catalog=Eloan365;Integrated Security=True;MultipleActiveResultSets=False;Packet Size=4096;Application Name="Microsoft SQL Server Management Studio""
            providerName="System.Data.SqlClient" />
    </connectionStrings>
    <appSettings>
<add key="w116255175211/SQLEXPRESS" value="Data Source=(local);Initial Catalog=Eloan365;User ID=sa;Password=zzidc2012;Max Pool Size=2000" />

<add key="DictionaryFolder" value="bin" />
     </appSettings>
    <system.web>
      <httpHandlers>
        <add verb="POST,GET" path="ajaxpro/*.ashx" type="AjaxPro.AjaxHandlerFactory, AjaxPro.2"/>      </httpHandlers>
      <pages enableEventValidation="true">

      </pages>
      <sessionState mode="InProc" stateConnectionString="tcpip=127.0.0.1:42424" sqlConnectionString="data source=(local);Trusted_Connection=yes"  cookieless="false" timeout="60"/>
      <browserCaps>      tagwriter=System.Web.UI.HtmlTextWriter    </browserCaps>
        
        <compilation debug="true" />
        
        <authentication mode="Windows" />
      <customErrors mode="Off"/>
        
    </system.web>
后台管理页
<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="AdminIndex.aspx.cs" Inherits="ELOAN365.AdminManage.AdminIndex" %>
<!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>后台管理</title>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" /><style type="text/css">

</style>  <link href="../css.css" rel="stylesheet" type="text/css" /><link href="../default.css" rel="stylesheet" type="text/css" /></head>
<body>
    <form id="form1" runat="server">
    <table width="100%" border="0" cellspacing="0" cellpadding="0">
  <tr>
    <td  width="180"  height="650">  <iframe src="leftmenu.aspx" id="leftmenu" name="leftmenu"   width=100% height=100% frameborder="1" scrolling="auto"> </iframe>
         </td>
    <td  height="650" valign="top"> <iframe src="Main.aspx" id="imain" name="imain"   width=100% height=100% frameborder="1" scrolling="auto"> </iframe> </td>
  </tr>
</table>
    </form>
</body>
</html>