使用 StructureMap 的 NLog GetCurrentClassLogger() NullReferenceException（完全信任）

Question

尽管我的 MVC 3 应用程序部署在 IIS7 上的完全信任环境中，但 NLog 似乎无法对 GetCurrentClassLogger() 使用反射。我正在使用 StructureMap 2.6.1，问题似乎在部署之间偶尔出现。我不明白为什么，尽管我不认为 StructureMap 造成了它。

Bootstrapper 类：

public static class Bootstrapper
{
    public static void ConfigureStructureMap()
    {
        ObjectFactory.Initialize(Init);
    }

    private static void Init(IInitializationExpression x)
    {
        x.AddRegistry(new DBServiceRegistry());
        x.AddRegistry(new MyRegistry());
    }
}

Registry 类：

public class MyRegistry : Registry
{
    public MyRegistry()//HttpContext context)
    {
        For<ILogger>().Use<NLogLogger>();
        For<IUserRepository>().Use<SqlUserRepository>();
    }
}

在我的机器上一切都运行良好。为什么我在部署时收到 System.NullReferenceException：未将对象引用设置为对象实例 错误？

[NullReferenceException: Object reference not set to an instance of an object.]
   NLog.LogManager.GetCurrentClassLogger() +84
   lambda_method(Closure , IArguments ) +40
   StructureMap.Construction.<>c__DisplayClass2.<CreateBuilder>b__0(IArguments args) +22
   StructureMap.Construction.InstanceBuilder.BuildInstance(IArguments args) +12
   StructureMap.Pipeline.ConstructorInstance.Build(Type pluginType, BuildSession session, IInstanceBuilder builder) +88

[StructureMapException: StructureMap Exception Code:  207
Internal exception while creating Instance '38000383-149d-45c2-a8f3-7442316da725' of PluginType Todo.Data.ILogger.  Check the inner exception for more details.]
   StructureMap.Pipeline.ConstructorInstance.Build(Type pluginType, BuildSession session, IInstanceBuilder builder) +276
   StructureMap.Pipeline.ConstructorInstance.build(Type pluginType, BuildSession session) +41
   StructureMap.Pipeline.SmartInstance_1.build(Type pluginType, BuildSession session) +43
   StructureMap.Pipeline.Instance.createRawObject(Type pluginType, BuildSession session) +45
   StructureMap.Pipeline.Instance.Build(Type pluginType, BuildSession session) +36
   StructureMap.Pipeline.ObjectBuilder.Resolve(Type pluginType, Instance instance, BuildSession session) +103
   StructureMap.BuildSession.CreateInstance(Type pluginType, Instance instance) +49
   StructureMap.<>c__DisplayClass3.<.ctor>b__1() +22
   StructureMap.BuildSession.CreateInstance(Type pluginType) +24
   ...etc...snipped

Answer 1

事实证明这不是信任问题，而是 IoC 问题。感谢 NInject 解决方案为我提供指导朝着正确的方向。

解决方案

对于您的日志记录包装器，请使用接受字符串参数的构造函数：

public class NLogLogger : ILogger
{
    private Logger _logger;

    public NLogLogger(string currentClassName)
    {
        _logger = LogManager.GetLogger(currentClassName);
    }
    ...
}

NLog StructureMap 配置：

For<ILogger>().Use<NLogLogger>()
    .Ctor<string>("currentClassName")
    .Is(x => x.BuildStack.Root.RequestedType.FullName);