IIS不显示网页

Question

我在编译/调试我的 Web 应用程序时没有任何问题，但是当我尝试从 IIS 服务器运行它时，我收到此错误：

Server Error in '/' Application.

Object reference not set to an instance of an object.

Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. 

Exception Details: System.NullReferenceException: Object reference not set to an instance of an object.

Source Error: 

An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.

Stack Trace: 


[NullReferenceException: Object reference not set to an instance of an object.]
   EnterData.Global.Application_AuthenticateRequest(Object sender, EventArgs e) in C:\Users\agordon\Documents\Visual Studio 2008\Projects\lomdb\EnterData\Global.asax.cs:30
   System.Web.SyncEventExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +79
   System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +170

Version Information: Microsoft .NET Framework Version:2.0.50727.5448; ASP.NET Version:2.0.50727.5420

我已经完成：

aspnet_regiis -ua
aspnet_regiis -i

并且我已重新启动计算机，

它是 Windows 7，IIS 7

Web 应用程序在不同的计算机上工作正常

我该如何解决这个问题？我做错了什么？

在堆栈跟踪的第 30 行我有（字符串用户名......）：

protected void Application_AuthenticateRequest(object sender, EventArgs e)
{
    string username = HttpContext.Current.User.Identity.Name.ToString();

    bool yesno = HttpContext.Current.User.IsInRole("Group0Users");

    string role = GetRole.OfUser(username);

}

这是 web.config 文件：

<?xml version="1.0"?><configuration>

    <configSections>
        <sectionGroup name="system.web.extensions" type="System.Web.Configuration.SystemWebExtensionsSectionGroup, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35">
            <sectionGroup name="scripting" type="System.Web.Configuration.ScriptingSectionGroup, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35">
                <section name="scriptResourceHandler" type="System.Web.Configuration.ScriptingScriptResourceHandlerSection, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" requirePermission="false" allowDefinition="MachineToApplication"/>
                <sectionGroup name="webServices" type="System.Web.Configuration.ScriptingWebServicesSectionGroup, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35">
                    <section name="jsonSerialization" type="System.Web.Configuration.ScriptingJsonSerializationSection, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" requirePermission="false" allowDefinition="Everywhere"/>
                    <section name="profileService" type="System.Web.Configuration.ScriptingProfileServiceSection, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" requirePermission="false" allowDefinition="MachineToApplication"/>
                    <section name="authenticationService" type="System.Web.Configuration.ScriptingAuthenticationServiceSection, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" requirePermission="false" allowDefinition="MachineToApplication"/>
                    <section name="roleService" type="System.Web.Configuration.ScriptingRoleServiceSection, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" requirePermission="false" allowDefinition="MachineToApplication"/>


                </sectionGroup>
            </sectionGroup>
        </sectionGroup>
    </configSections>

  <location path="default.aspx">
    <system.web>
      <authorization>
        <allow roles="mlabs\Group2Users"/>
        <deny users="*"/>
      </authorization>
    </system.web>
  </location>

  <appSettings>
    <add key="dePracticeErrors" value="agordon,user1,user2,user3"/>
    <add key="dePreAnalytical" value="user2,mlabs\\agordon,user1,user3"/>
  </appSettings>


  <connectionStrings>
    <add name="qcvalues_testConnectionString" connectionString="Data Source=hermes;Initial Catalog=qcvalues_test;Integrated Security=True" providerName="System.Data.SqlClient"/>
    <add name="LOMConnectionString" connectionString="Data Source=GAIA;Initial Catalog=LOM;Integrated Security=True" providerName="System.Data.SqlClient"/>
    <add name="LOMold" providerName="System.Data.SqlClient"
       connectionString="server=GAIA; database=LOM; Integrated Security=false; user=lomuser; password=M1llenium92127" />
    <add name="LOM" connectionString="Data Source=gaia;Initial Catalog=LOM;Integrated Security=True" providerName="System.Data.SqlClient"/>

  </connectionStrings>
    <system.web>
        <!-- 
            Set compilation debug="true" to insert debugging 
            symbols into the compiled page. Because this 
            affects performance, set this value to true only 
            during development.
        -->
    <roleManager enabled="true" defaultProvider="AspNetWindowsTokenRoleProvider"/>


   <authorization>

  </authorization>


  <compilation debug="true">
            <assemblies>
                <add assembly="System.Core, Version=3.5.0.0, Culture=neutral, PublicKeyToken=B77A5C561934E089"/>
                <add assembly="System.Data.DataSetExtensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=B77A5C561934E089"/>
                <add assembly="System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
                <add assembly="System.Xml.Linq, Version=3.5.0.0, Culture=neutral, PublicKeyToken=B77A5C561934E089"/>

                <add assembly="System.Web.Extensions.Design, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
                <add assembly="System.Design, Version=2.0.0.0, Culture=neutral, PublicKeyToken=B03F5F7F11D50A3A"/>
                <add assembly="System.Windows.Forms, Version=2.0.0.0, Culture=neutral, PublicKeyToken=B77A5C561934E089"/></assemblies>
        </compilation>
        <!--
            The <authentication> section enables configuration 
            of the security authentication mode used by 
            ASP.NET to identify an incoming user. 
        -->
  <!--
            The <customErrors> section enables configuration 
            of what to do if/when an unhandled error occurs 
            during the execution of a request. Specifically, 
            it enables developers to configure html error pages 
            to be displayed in place of a error stack trace.

        <customErrors mode="RemoteOnly" defaultRedirect="GenericErrorPage.htm">
            <error statusCode="403" redirect="NoAccess.htm" />
            <error statusCode="404" redirect="FileNotFound.htm" />
        </customErrors>
        -->
        <pages>
            <controls>
                <add tagPrefix="asp" namespace="System.Web.UI" assembly="System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
                <add tagPrefix="asp" namespace="System.Web.UI.WebControls" assembly="System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
            </controls>
        </pages>
        <httpHandlers>
            <remove verb="*" path="*.asmx"/>
            <add verb="*" path="*.asmx" validate="false" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
            <add verb="*" path="*_AppService.axd" validate="false" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
            <add verb="GET,HEAD" path="ScriptResource.axd" type="System.Web.Handlers.ScriptResourceHandler, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" validate="false"/>
        </httpHandlers>
        <httpModules>
            <add name="ScriptModule" type="System.Web.Handlers.ScriptModule, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
        </httpModules>
    </system.web>
    <system.codedom>
        <compilers>
            <compiler language="c#;cs;csharp" extension=".cs" warningLevel="4" type="Microsoft.CSharp.CSharpCodeProvider, System, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">
                <providerOption name="CompilerVersion" value="v3.5"/>
                <providerOption name="WarnAsError" value="false"/>
            </compiler>
        </compilers>
    </system.codedom>
    <!-- 
        The system.webServer section is required for running ASP.NET AJAX under Internet
        Information Services 7.0.  It is not necessary for previous version of IIS.
    -->
    <system.webServer>
        <validation validateIntegratedModeConfiguration="false"/>
        <modules>
            <remove name="ScriptModule"/>
            <add name="ScriptModule" preCondition="managedHandler" type="System.Web.Handlers.ScriptModule, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
        </modules>

        <handlers>

            <remove name="WebServiceHandlerFactory-Integrated"/>
            <remove name="ScriptHandlerFactory"/>
            <remove name="ScriptHandlerFactoryAppServices"/>
            <remove name="ScriptResource"/>
            <add name="ScriptHandlerFactory" verb="*" path="*.asmx" preCondition="integratedMode" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
            <add name="ScriptHandlerFactoryAppServices" verb="*" path="*_AppService.axd" preCondition="integratedMode" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
            <add name="ScriptResource" preCondition="integratedMode" verb="GET,HEAD" path="ScriptResource.axd" type="System.Web.Handlers.ScriptResourceHandler, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
        </handlers>
    </system.webServer>
    <runtime>
        <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
            <dependentAssembly>
                <assemblyIdentity name="System.Web.Extensions" publicKeyToken="31bf3856ad364e35"/>
                <bindingRedirect oldVersion="1.0.0.0-1.1.0.0" newVersion="3.5.0.0"/>
            </dependentAssembly>
            <dependentAssembly>
                <assemblyIdentity name="System.Web.Extensions.Design" publicKeyToken="31bf3856ad364e35"/>
                <bindingRedirect oldVersion="1.0.0.0-1.1.0.0" newVersion="3.5.0.0"/>
            </dependentAssembly>
        </assemblyBinding>
    </runtime>
</configuration>

Answer 1

查看堆栈跟踪，距离底部大约 4 行。它说它在 Global.asax.cs 第 30 行遇到错误。无论该行的代码是什么，它都会尝试处理具有空值的变量中的数据。

您需要找出该变量为何为空​​的原因，并解决根本问题。请随意将该代码发布到这个问题中，以便我们能够真正帮助您排除故障。

编辑：
从您的代码来看，您需要在此服务器上设置 IIS 身份验证。将“身份验证”设置为“Windows”，然后取消选中“允许匿名访问”。

Answer 2

将您的代码更改为

if ( HttpContext.Current.User != null )
{
     if ( HttpContext.Current.User.Identity != null )
          {
          string username = HttpContext.Current.User.Identity.Name.ToString();

          bool yesno = HttpContext.Current.User.IsInRole("Group0Users");

          string role = GetRole.OfUser(username);
          }

}

BTW：GetRole.OfUser 中的代码也需要检查 null ！

Answer 3

最有可能的情况是 ToString() 调用抛出空引用异常。

因此，首先向后检查 HttpContext.Current.User.Identity.Name 是否为 null。如果是，请继续向后工作，直到找到第一个非空值。您最后剥离的属性是您需要进行空检查的属性。

例如，假设 HttpContext.Current.User 为非空（希望如此）。然后您需要在代码中对 Identity 进行空检查：

if(HttpContext.Current.User.Identity != null)
{
   string username = HttpContext.Current.User.Identity.Name.ToString();
   //rest of your code...
}

HTH