如何在包装NLog时保留呼叫站点信息

我有一个包装NLog的类（称为NLogger）。 我的日志保存到我的数据库中。 我遇到问题的是如何显示日志记录的位置。 我有这个

但这只是显示Core.Logging.Loggers.NLogLogger.Log这是我的NlogWrapper而不是调用我的包装器的类。

这是我的包装方法

  public void Log(LogType messageType, Type context, string message, Exception exception) { NLog.Logger logger = NLog.LogManager.GetLogger(context.Name); LogLevel logLevel = LogLevel.Info; // Default level to info switch (messageType) { case LogType.Debug: logLevel = LogLevel.Debug; break; case LogType.Info: logLevel = LogLevel.Info; break; case LogType.Warning: logLevel = LogLevel.Warn; break; case LogType.Error: logLevel = LogLevel.Error; break; case LogType.Fatal: logLevel = LogLevel.Fatal; break; default: throw new ArgumentException("Log message type is not supported"); } logger.Log(logLevel, message, exception); } 

Answer 1

问题是你的包装器没有正确包装。 下面是一个如何正确包装NLog的示例，直接从NLog的源代码树中获取 ：

 using System; using System.Text; using NLog; namespace LoggerWrapper { /// 
 /// Provides methods to write messages with event IDs - useful for the Event Log target. /// Wraps a Logger instance. /// 
 class MyLogger { private Logger _logger; public MyLogger(string name) { _logger = LogManager.GetLogger(name); } public void WriteMessage(string eventID, string message) { /// /// create log event from the passed message /// LogEventInfo logEvent = new LogEventInfo(LogLevel.Info, _logger.Name, message); // // set event-specific context parameter // this context parameter can be retrieved using ${event-context:EventID} // logEvent.Context["EventID"] = eventID; // // Call the Log() method. It is important to pass typeof(MyLogger) as the // first parameter. If you don't, ${callsite} and other callstack-related // layout renderers will not work properly. // _logger.Log(typeof(MyLogger), logEvent); } } } 

关键是将记录器包装器的类型传递给对Log的调用。 当NLog试图找到呼叫站点时，它会上升到堆栈，直到第一个调用方法的声明类型不是传递给Log调用的类型。 这将是实际调用您的包装器的代码。

在您的情况下，您的记录器看起来像这样：

  public void Log(LogType messageType, Type context, string message, Exception exception) { NLog.Logger logger = NLog.LogManager.GetLogger(context.Name); LogLevel logLevel = LogLevel.Info; // Default level to info switch (messageType) { case LogType.Debug: logLevel = LogLevel.Debug; break; case LogType.Info: logLevel = LogLevel.Info; break; case LogType.Warning: logLevel = LogLevel.Warn; break; case LogType.Error: logLevel = LogLevel.Error; break; case LogType.Fatal: logLevel = LogLevel.Fatal; break; default: throw new ArgumentException("Log message type is not supported"); } // // Build LogEvent here... // LogEventInfo logEvent = new LogEventInfo(logLevel, context.Name, message); logEvent.Exception = exception; // // Pass the type of your wrapper class here... // logger.Log(typeof(YourWrapperClass), logEvent); } 

Answer 2

要跳过几帧并深入了解包装调用者上下文，请在App.config中设置，或者在程序中设置着名的修饰符：

skipFrames = 1

示例：请参阅此页面以获取${callsite:skipFrames=Integer} 此页面的${callsite-linenumber:skipFrames=Integer}

我建议你在你的包装器中使用这种格式：

 ${callsite:fileName=true:includeSourcePath=false:skipFrames=1} 

此设置的输出如下：

… {LicenseServer.LSCore.MainThreadFunction（LSCore.cs：220）} …

Answer 3

 internal string GetCallingMethodName() { string result = "unknown"; StackTrace trace = new StackTrace(false); for (int i = 0; i < trace.FrameCount; i++) { StackFrame frame = trace.GetFrame(i); MethodBase method = frame.GetMethod(); Type dt = method.DeclaringType; if (!typeof(ILogger).IsAssignableFrom(dt) && method.DeclaringType.Namespace != "DiagnosticsLibrary") { result = string.Concat(method.DeclaringType.FullName, ".", method.Name); break; } } return result; } 

资料来源： http ： //slf.codeplex.com/discussions/210075

我使用上面发布的代码简单地提取调用方法名称，并将其作为“message”参数的一部分传递给布局。 这使我可以将调用日志包装器的原始方法名称写入日志文件（而不是日志包装器的类名）。

Answer 4

我一直在与这个问题作斗争。

真正重要的是日志文件中的Callsite（FullyQualified Namespace）。

首先，我试图从Stacktrace中获取正确的记录器：

  [MethodImpl(MethodImplOptions.NoInlining)] private static NLog.Logger GetLogger() { var stackTrace = new StackTrace(false); StackFrame[] frames = stackTrace.GetFrames(); if (null == frames) throw new ArgumentException("Stack frame array is null."); StackFrame stackFrame; switch (frames.Length) { case 0: throw new ArgumentException("Length of stack frames is 0."); case 1: case 2: stackFrame = frames[frames.Length - 1]; break; default: stackFrame = stackTrace.GetFrame(2); break; } Type declaringType = stackFrame.GetMethod() .DeclaringType; return declaringType == null ? LogManager.GetCurrentClassLogger() : LogManager.GetLogger(declaringType.FullName); } 

但遗憾的是，带有MEF的Stacktrace非常长，我无法清楚地识别ILogger请求者的正确调用者。

因此，我没有通过构造函数注入注入ILogger接口，而是创建了一个ILogFactory接口，可以通过构造函数注入注入，然后调用工厂上的Create方法

  public interface ILogFactory { #region Public Methods and Operators /// 
 /// Creates a logger with the Callsite of the given Type /// 
 ///  /// factory.Create(GetType()); ///  /// The type. ///  ILogger Create(Type type); #endregion } 

并实施了它：

  using System; using System.ComponentModel.Composition; [Export(typeof(ILogFactory))] [PartCreationPolicy(CreationPolicy.Shared)] public class LogFactory : ILogFactory { #region Public Methods and Operators public ILogger Create(Type type) { var logger = new Logger().CreateLogger(type); return logger; } #endregion } 

使用ILogger：

  public interface ILogger { #region Public Properties bool IsDebugEnabled { get; } bool IsErrorEnabled { get; } bool IsFatalEnabled { get; } bool IsInfoEnabled { get; } bool IsTraceEnabled { get; } bool IsWarnEnabled { get; } #endregion #region Public Methods and Operators void Debug(Exception exception); void Debug(string format, params object[] args); void Debug(Exception exception, string format, params object[] args); void Error(Exception exception); void Error(string format, params object[] args); void Error(Exception exception, string format, params object[] args); void Fatal(Exception exception); void Fatal(string format, params object[] args); void Fatal(Exception exception, string format, params object[] args); void Info(Exception exception); void Info(string format, params object[] args); void Info(Exception exception, string format, params object[] args); void Trace(Exception exception); void Trace(string format, params object[] args); void Trace(Exception exception, string format, params object[] args); void Warn(Exception exception); void Warn(string format, params object[] args); void Warn(Exception exception, string format, params object[] args); #endregion } 

和实施：

  using System; using NLog; using NLog.Config; /// 
 /// The logging service. /// 
 public class Logger : NLog.Logger, ILogger { #region Fields private string _loggerName; #endregion #region Public Methods and Operators /// 
 /// The get logging service. /// 
 ///  /// The . ///  public ILogger CreateLogger(Type type) { if (type == null) throw new ArgumentNullException("type"); _loggerName = type.FullName; var logger = (ILogger)LogManager.GetLogger(_loggerName, typeof(Logger)); return logger; } 

要使用它…只需注入ILogFactory并在Mefed导入构造函数中调用Create方法：

  [ImportingConstructor] public MyConstructor( ILogFactory logFactory) { _logger = logFactory.Create(GetType()); } 

希望这可以帮助

Answer 5

或者，您可以避免NLog设置的本机解决方案，并检索文件 方法| 包装器代码中的行信息：

 using System.Diagnostics; ... static private string GetCallsite() { StackFrame sf = new StackTrace(2/*Skip two frames - dive to the callers context*/, true/*Yes I want the file info !*/).GetFrame(0); return "{" + sf.GetFileName() + " | " + sf.GetMethod().Name + "-" + sf.GetFileLineNumber() + "} "; } 

然后你只需调用静态方法并在消息之前添加callsite：

 LogManager.GetCurrentClassLogger().Trace(GetCallsite() + "My Trace Message."); 

Answer 6

伙计经过几天的艰苦努力和搜索。最后，我只使用一个简单的类构建了Nlog Wrapper，它可以保留$ {callsite}并在创建Nlog Wrapper实例时获取正确的记录器名称。 我将把代码放在简单的注释之后。 如您所见，我使用Stacktrace来获得正确的记录器名称。 使用write和writewithex注册logevnet，以便保留callsite。

  public class NlogWrapper { private readonly NLog.Logger _logger; //NLog logger /// 
 /// This is the construtor, which get the correct logger name when instance created /// 
 public NlogWrapper() { StackTrace trace = new StackTrace(); if (trace.FrameCount > 1) { _logger = LogManager.GetLogger(trace.GetFrame(1).GetMethod().ReflectedType.FullName); } else //This would go back to the stated problem { _logger = LogManager.GetCurrentClassLogger(); } } /// 
 /// These two method are used to retain the ${callsite} for all the Nlog method /// 
 /// LogLevel. /// Passed message. /// Exception. private void Write(LogLevel level, string format, params object[] args) { LogEventInfo le = new LogEventInfo(level, _logger.Name, null, format, args); _logger.Log(typeof(NlogWrapper), le); } private void WriteWithEx(LogLevel level, string format,Exception ex, params object[] args) { LogEventInfo le = new LogEventInfo(level, _logger.Name, null, format, args); le.Exception = ex; _logger.Log(typeof(NlogWrapper), le); } #region Methods /// 
 /// This method writes the Debug information to trace file /// 
 /// The message. public void Debug(String message) { if (!_logger.IsDebugEnabled) return; Write(LogLevel.Debug, message); } public void Debug(string message, Exception exception, params object[] args) { if (!_logger.IsFatalEnabled) return; WriteWithEx(LogLevel.Debug, message, exception); } /// 
 /// This method writes the Information to trace file /// 
 /// The message. public void Info(String message) { if (!_logger.IsInfoEnabled) return; Write(LogLevel.Info, message); } public void Info(string message, Exception exception, params object[] args) { if (!_logger.IsFatalEnabled) return; WriteWithEx(LogLevel.Info, message, exception); } /// 
 /// This method writes the Warning information to trace file /// 
 /// The message. public void Warn(String message) { if (!_logger.IsWarnEnabled) return; Write(LogLevel.Warn, message); } public void Warn(string message, Exception exception, params object[] args) { if (!_logger.IsFatalEnabled) return; WriteWithEx(LogLevel.Warn, message, exception); } /// 
 /// This method writes the Error Information to trace file /// 
 /// The error. /// The exception. // public static void Error( string message) // { // if (!_logger.IsErrorEnabled) return; // _logger.Error(message); //} public void Error(String message) { if (!_logger.IsWarnEnabled) return; //_logger.Warn(message); Write(LogLevel.Error, message); } public void Error(string message, Exception exception, params object[] args) { if (!_logger.IsFatalEnabled) return; WriteWithEx(LogLevel.Error, message, exception); } /// 
 /// This method writes the Fatal exception information to trace target /// 
 /// The message. public void Fatal(String message) { if (!_logger.IsFatalEnabled) return; Write(LogLevel.Fatal, message); } public void Fatal(string message, Exception exception, params object[] args) { if (!_logger.IsFatalEnabled) return; WriteWithEx(LogLevel.Fatal, message, exception); } /// 
 /// This method writes the trace information to trace target /// 
 /// The message. /// public void Trace(string message, Exception exception, params object[] args) { if (!_logger.IsFatalEnabled) return; WriteWithEx(LogLevel.Trace, message, exception); } public void Trace(String message) { if (!_logger.IsTraceEnabled) return; Write(LogLevel.Trace, message); } #endregion }