title: log4net on Windows Forms doesn't write log file
body: <p>I'm developing a Windows Form app with .NET Framework 4.0 and log4net 1.2.13.</p>
  
  <p>This is the first time I use log4net in a Windows Form application and it doesn't work. Maybe I forget a configuration step nut now, it doesn't work: <strong>I can't find the log file</strong>.</p>
  
  <p>This is how I instance logger:</p>
  
  <pre><code>public partial class MainForm : Form
  {
      private static readonly log4net.ILog _logger =
          log4net.LogManager.GetLogger(typeof(MainForm));
  </code></pre>
  
  <p>And this is App.Config contents:</p>
  
  <pre><code>&lt;log4net xsi:noNamespaceSchemaLocation="http://csharptest.net/downloads/schema/log4net.xsd" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"&gt;
    &lt;appender type="log4net.Appender.RollingFileAppender" name="AppLogErrorAppender"&gt;
      &lt;file value="D:\\AppError.log" /&gt;
      &lt;appendToFile value="true" /&gt;
      &lt;rollingStyle value="Date" /&gt;
      &lt;datePattern value=".yyyyMMdd.lo\g" /&gt;
      &lt;maximumFileSize value="5MB" /&gt;
      &lt;maxSizeRollBackups value="-1" /&gt;
      &lt;countDirection value="1" /&gt;
      &lt;layout type="log4net.Layout.PatternLayout"&gt;
        &lt;conversionPattern value="%date %-5level [%thread] %logger - %message%newline%exception" /&gt;
      &lt;/layout&gt;
    &lt;/appender&gt;
    &lt;appender name="ConsoleAppender" type="log4net.Appender.ConsoleAppender"&gt;
      &lt;layout type="log4net.Layout.PatternLayout"&gt;
        &lt;conversionPattern value="%date %-5level [%thread] %logger - %message%newline%exception" /&gt;
      &lt;/layout&gt;
    &lt;/appender&gt;
    &lt;logger name="AppLog"&gt;
      &lt;level value="ERROR" /&gt;
      &lt;appender-ref ref="AppLogErrorAppender" /&gt;
    &lt;/logger&gt;
    &lt;root&gt;
        &lt;level value="ERROR" /&gt;
        &lt;appender-ref ref="AppLogErrorAppender" /&gt;
        &lt;appender-ref ref="ConsoleAppender" /&gt;
    &lt;/root&gt;
  &lt;/log4net&gt;
  </code></pre>
  
  <p>I'm logging here:</p>
  
  <pre><code>public const string LogExceptionNameMessageFormatString = "EXCEPTION: {0} - Message: {1}";
  
  private void LogError(string exceptionMessage, string exceptionName)
  {
      _logger.ErrorFormat(LogExceptionNameMessageFormatString, exceptionName, exceptionMessage);
  }
  </code></pre>
  
  <p>I have a breakpoint on it, and it stops.</p>
  
  <p>What am I doing wrong?</p>