Question

I am using log4net.

When Application gives an error, I want to send e-mail just for errors. How should I do that ?

My Config File :

<configuration>
  <configSections>
    <section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler,log4net" />
  </configSections>
  <log4net>
    <appender name="SMTPAppender" type="log4net.Appender.SMTPAppender">
      <authentication value="Basic" />
      <to value="xxx@xxx" />
      <from value="yyy@yyy" />
      <username value="user" />
      <password value="pass" />
      <subject value="ERROR" />
      <smtpHost value="host" />
      <port value="25" />
      <lossy value="true" />
      <evaluator type="log4net.Core.LevelEvaluator">
        <threshold value="WARN" />
      </evaluator>
      <layout type="log4net.Layout.PatternLayout">
        <conversionPattern value="%newline%date [%thread] %-5level %logger %newline %message%newline%newline%newline" />
      </layout>
    </appender>
    <root>
      <level value="INFO"></level>
    </root>
    <logger name="SMTPAppender">
      <level value="INFO"></level>
      <appender-ref ref="SMTPAppender"></appender-ref>
    </logger>
  </log4net>
</configuration>

I am trying to test in NUnit:

[TestFixture]
public class TestClass
{
    [Test]
    public void Test()
    {
        ILog logger = LogManager.GetLogger(typeof(TestClass));
        logger.Error("test mail");
    }
}

I am probably doing something wrong.

EDIT:

<logger name="Yuartz.Tests.TestClass">
  <level value="INFO"></level>
  <appender-ref ref="SMTPAppender"></appender-ref>
</logger>

namespace Yuartz.Tests
{
    using log4net;
    using log4net.Config;

    [TestFixture]
    public class TestClass
    {
        [Test]
        public void Test()
        {
            XmlConfigurator.Configure();
            var logger = LogManager.GetLogger("SMTPAppender");
            logger.Error("test mail");
            logger.Info("test mail");
        }
    }
}

Answer 1

In your example you use the full name of the type (TestClass) to retrieve your logger. It will use this name to resolve the logger or create a new one when not found.

ILog logger = LogManager.GetLogger(typeof(TestClass));

If you want this line of code to return the SMTPAppender logger, then you need to rename it in the config as follows:

<logger name="Yuartz.Tests.TestClass">
    ...
</logger>

If you don’t want to change the configuration then you need to retrieve your logger by its actual name. The following returns the logger named “SMTPAppender”.

var logger = LogManager.GetLogger("SMTPAppender");

My advice is to just change the name in the configuration and keep retrieving the logger by type as you currently do.

Also make sure that you read your configuration.

log4net.Config.XmlConfigurator.Configure();