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发生的位置。 我有这个
<parameter name="@Logger" layout="${callsite}"/>
但是这只显示了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);
}
答案 0 :(得分：40)
问题是你的包装器没有正确包装。以下是如何正确包装NLog的示例，直接取自source tree of NLog：
using System;
using System.Text;
using NLog;
namespace LoggerWrapper
{
/// <summary>
/// Provides methods to write messages with event IDs - useful for the Event Log target.
/// Wraps a Logger instance.
/// </summary>
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, ${callsite} and other callstack-related
// layout renderers will not work properly.
//
_logger.Log(typeof(MyLogger), logEvent);
}
}
}
密钥是将记录器包装器的类型传递给对Log的调用。当NLog试图找到呼叫站点时，它会上升到堆栈，直到第一个调用方法的声明类型不是传递给Log调用的类型。这将是实际调用您的包装器的代码。
在您的情况下，您的记录器看起来像这样：
public void Log(LogType messageType, Type context, string message, Exception exception)
{
NLog.Logger logger = NLog.LogManager.GetLogger(context.Name);
LogLevel logLevel = LogLevel.Info; // Default level to info
switch (messageType)
{
case LogType.Debug:
logLevel = LogLevel.Debug;
break;
case LogType.Info:
logLevel = LogLevel.Info;
break;
case LogType.Warning:
logLevel = LogLevel.Warn;
break;
case LogType.Error:
logLevel = LogLevel.Error;
break;
case LogType.Fatal:
logLevel = LogLevel.Fatal;
break;
default:
throw new ArgumentException("Log message type is not supported");
}
//
// Build LogEvent here...
//
LogEventInfo logEvent = new LogEventInfo(logLevel, context.Name, message);
logEvent.Exception = exception;
//
// Pass the type of your wrapper class here...
//
logger.Log(typeof(YourWrapperClass), logEvent);
}
答案 1 :(得分：10)
跳过几帧并深入了解包装调用者上下文，在App.config中设置，或在程序中使用着名的修饰符：
skipFrames = 1
实施例：
有关${callsite:skipFrames=Integer}的信息，请参见this page
和${callsite-linenumber:skipFrames=Integer}
我建议你在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）} ...
答案 2 :(得分：2)
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;
}
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。这使得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）。
答案 3 :(得分：2)
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，我无法清楚地识别出ILogger请求者的正确来电者。
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
/// <summary>
/// Creates a logger with the Callsite of the given Type
/// </summary>
/// <example>
/// factory.Create(GetType());
/// </example>
/// <param name="type">The type.</param>
/// <returns></returns>
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;
/// <summary>
/// The logging service.
/// </summary>
public class Logger : NLog.Logger, ILogger
{
#region Fields
private string _loggerName;
#endregion
#region Public Methods and Operators
/// <summary>
/// The get logging service.
/// </summary>
/// <returns>
/// The <see cref="ILogger" />.
/// </returns>
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;
}
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());
}
希望这会有所帮助
答案 4 :(得分：0)
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：
LogManager.GetCurrentClassLogger().Trace(GetCallsite() + "My Trace Message.");
然后你只需调用静态方法并在消息之前添加callsite：
await RepositoryHelper.UpdateDonation
await RepositoryHelper.AddFreeUsers
await RepositoryHelper.UpgradeToPaid
await SendUserPaymentConfirmed
答案 5 :(得分：0)
专家 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获取正确的记录器名称。使用write和writewithex来注册logevnet，以便保留callsite。
public class NlogWrapper
{
private readonly NLog.Logger _logger; //NLog logger
/// <summary>
/// This is the construtor, which get the correct logger name when instance created
/// </summary>
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();
}
}
/// <summary>
/// These two method are used to retain the ${callsite} for all the Nlog method
/// </summary>
/// <param name="level">LogLevel.</param>
/// <param name="format">Passed message.</param>
/// <param name="ex">Exception.</param>
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
/// <summary>
/// This method writes the Debug information to trace file
/// </summary>
/// <param name="message">The message.</param>
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);
}
/// <summary>
/// This method writes the Information to trace file
/// </summary>
/// <param name="message">The message.</param>
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);
}
/// <summary>
/// This method writes the Warning information to trace file
/// </summary>
/// <param name="message">The message.</param>
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);
}
/// <summary>
/// This method writes the Error Information to trace file
/// </summary>
/// <param name="error">The error.</param>
/// <param name="exception">The exception.</param>
// 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);
}
/// <summary>
/// This method writes the Fatal exception information to trace target
/// </summary>
/// <param name="message">The message.</param>
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);
}
/// <summary>
/// This method writes the trace information to trace target
/// </summary>
/// <param name="message">The message.</param>
///
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
}
答案 6 :(得分：0)
有一个简单的方法可以实现这一目标。只需将这些属性添加到您的日志包装器方法签名中即可：
void Log(LogSeverity severity, string message, [CallerFilePath] string fileName = null, [CallerMemberName] string member = null, [CallerLineNumber] int? lineNumber = null);
并将其传递给包装的NLog方法。
有关{.3中的System.Runtime.CompilerServices服装的更多信息，请参见https://docs.microsoft.com/en-us/dotnet/api/system.runtime.compilerservices.callerfilepathattribute?view=netframework-4.7.2。
答案 7 :(得分：0)
如今，修复呼叫站点的一种更简单的方法是使用LogManager.AddHiddenAssembly(Assembly)
例如
LogManager.AddHiddenAssembly(yourAssembly);
这将修复呼叫站点，而无需进行手动堆栈遍历等。