包装 NLog 时如何保留调用站点信息
本文关键字：保留 调用 站点 信息 NLog 何保留 包装 | 更新日期: 2023-09-27 18:08:44
我有一个包装NLog的类(称为NLogger(。我的日志将保存到我的数据库中。我遇到的问题是如何显示日志记录发生的位置。我有这个
<parameter name="@Logger" layout="${callsite}"/>
但这只显示 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);
}
问题是您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，直接取自 NLog 的源代码树：
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, ${callsite} and other callstack-related
// layout renderers will not work properly.
//
_logger.Log(typeof(MyLogger), logEvent);
}
}
}
关键是将记录器包装器的类型传递给对 Log 的调用。 当 NLog 尝试查找调用站点时，它会在堆栈中向上移动，直到第一个调用方法的声明类型不是传递给 Log 调用的类型。 这将是实际调用包装器的代码。
在您的情况下，您的记录器将如下所示：
public void Log(LogType messageType, Type context, string message, Exception exception)
{
NLog.Logger logger = NLog.LogManager.GetLogger(context.Name);
LogLevel logLevel = LogLevel.Info; // Default level to info
switch (messageType)
{
case LogType.Debug:
logLevel = LogLevel.Debug;
break;
case LogType.Info:
logLevel = LogLevel.Info;
break;
case LogType.Warning:
logLevel = LogLevel.Warn;
break;
case LogType.Error:
logLevel = LogLevel.Error;
break;
case LogType.Fatal:
logLevel = LogLevel.Fatal;
break;
default:
throw new ArgumentException("Log message type is not supported");
}
//
// Build LogEvent here...
//
LogEventInfo logEvent = new LogEventInfo(logLevel, context.Name, message);
logEvent.Exception = exception;
//
// Pass the type of your wrapper class here...
//
logger.Log(typeof(YourWrapperClass), logEvent);
}
要跳过几帧并深入了解包装器调用方上下文，请在 App.config 中设置，或在程序中设置著名的修饰符：
跳过帧数=1
例子：请参阅此页面了解${callsite:skipFrames=Integer}和这个页面${callsite-linenumber:skipFrames=Integer}
我建议您在包装器中使用此格式：
${callsite:fileName=true:includeSourcePath=false:skipFrames=1}
此设置的输出如下所示：
。{LicenseServer.LSCore.MainThreadFunction(LSCore.cs：220(} ...
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来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(。
我已经
在与这个问题作斗争一段时间了。
真正重要的是日志文件中的调用站点(完全限定命名空间(。
首先，我试图从堆栈跟踪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 的堆栈跟踪很长，我无法清楚地识别 ILogger 请求者的正确调用方。
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，该接口可以通过构造函数注入并在工厂上调用 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
}
并实现了它：
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;
}
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());
}
希望这有帮助
如今修复
调用站点的更简单方法是使用LogManager.AddHiddenAssembly(Assembly)
例如
LogManager.AddHiddenAssembly(yourAssembly);
这将修复调用站点，无需进行手动堆栈遍历等。
或者，您可以避免从 NLog 设置中获取本机解决方案，并在包装器代码中检索文件 | 方法 | 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() + "} ";
}
然后你只需调用你的静态方法并在消息之前添加调用站点：
LogManager.GetCurrentClassLogger().Trace(GetCallsite() + "My Trace Message.");
伙计
们经过几天的努力和搜索。最后，我只使用一个简单的类构建了Nlog包装器，它可以保留${callsite}并在创建Nlog包装器实例时获得正确的记录器名称。我将把代码放在下面，并带有简单的注释。如您所见，我使用 Stacktrace 来获取正确的记录器名称。使用 write 和 writewithex 注册 logevnet，以便可以保留调用站点。
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
}
有一种简单的方法可以实现这一点。只需将这些属性添加到日志包装器方法签名中：
void Log(LogSeverity severity, string message, [CallerFilePath] string fileName = null, [CallerMemberName] string member = null, [CallerLineNumber] int? lineNumber = null);
并将这些传递给包装的 NLog 方法。
有关 .NET 中的 System.Runtime.CompilerServices 属性的详细信息，请参阅 https://learn.microsoft.com/en-us/dotnet/api/system.runtime.compilerservices.callerfilepathattribute?view=netframework-4.7.2。