如何使用log4net记录跟踪消息?

I'm using log4net to log write log message to a rolling log file.

我正在使用log4net将日志消息记录到滚动日志文件中。

Now I would also redirect all trace messages from System.Diagnostics.Trace to that log file. How can I configure that? I tried to find anything about that in the log4net documentation, but without success. Is it possible at all?

现在，我还将重定向来自System.Diagnostics的所有跟踪消息。跟踪到日志文件。我如何配置它?我试图在log4net文档中找到任何与此相关的内容，但没有成功。有可能吗?

The reason I want to do that is because I am interested in the Trace messages of a 3rd party library.

我这样做的原因是我对第三方库的跟踪消息感兴趣。

<log4net>
    <appender name="R1" type="log4net.Appender.RollingFileAppender">
      <file value="C:\Logs\MyService.log" />
      <appendToFile value="true" />
      <rollingStyle value="Date" />
      <maxSizeRollBackups value="10" />
      <datePattern value="yyyyMMdd" />
      <layout type="log4net.Layout.PatternLayout">
        <conversionPattern value="%date [%thread] %-5level %logger [%property{NDC}] - %message%newline" />
      </layout>
    </appender>
</log4net>

3 个解决方案

#1

According to Rune's suggestion I implemented a basic TraceListener which output to log4net:

根据Rune的建议，我实现了一个基本的TraceListener，输出到log4net:

public class Log4netTraceListener : System.Diagnostics.TraceListener
{
    private readonly log4net.ILog _log;

    public Log4netTraceListener()
    {
        _log = log4net.LogManager.GetLogger("System.Diagnostics.Redirection");
    }

    public Log4netTraceListener(log4net.ILog log)
    {
        _log = log;
    }

    public override void Write(string message)
    {
        if (_log != null)
        {
            _log.Debug(message);
        }
    }

    public override void WriteLine(string message)
    {
        if (_log != null)
        {
            _log.Debug(message);
        }
    }
}

#2

I don't know if log4net supports this, but you could implement your own trace listener that did this.

我不知道log4net是否支持这个，但是您可以实现自己的跟踪监听器。

The TraceListener doesn't have too many method that needs to be implemented and all you would do is to forward the values to log4net so this should be easy to do.

TraceListener没有太多需要实现的方法，您所要做的就是将值转发到log4net，因此这应该很容易实现。

To add a custom trace listener you would either modify your app.config/web.config or you would add it in code using Trace.Listeners.Add(new Log4NetTraceListener());

要添加自定义跟踪监听器，您可以修改app.config/web。配置，或者您可以使用trace.listener在代码中添加它。添加(新Log4NetTraceListener());

#3

As per the answers above, there's an implementation here (this link is flaky, but I did find the source code):

根据上面的答案，这里有一个实现(这个链接不可靠，但是我找到了源代码):

https://code.google.com/archive/p/cavity/

To crudely deal with the issue (described in the comments to a previous answer) of internal log4net trace issuing from the LogLog class, I checked for this class being the source of the trace by inspecting the stack frame (which this implementation did already) and ignoring those trace messages:

为了粗略地处理从LogLog类发出的内部log4net跟踪的问题(在前面的答案的注释中进行了描述)，我检查了堆栈框架(这个实现已经这样做了)，并忽略了这些跟踪消息:

    public override void WriteLine(object o, string category)
    {
        // hack to prevent log4nets own diagnostic trace getting fed back
        var method = GetTracingStackFrame(new StackTrace()).GetMethod();
        var declaringType = method.DeclaringType;
        if (declaringType == typeof(LogLog))
        {
            return;
        }
        /* rest of method writes to log4net */
    }

Using a TraceAppender will still create the problems described in the comments above.

使用TraceAppender仍然会产生上面评论中描述的问题。

#1