在wpf应用程序中创建错误日志

<log4net>
  <appender name="FileAppender" type="log4net.Appender.FileAppender">
    <file value="log.txt" />
   <appendToFile value="true" />
   <layout type="log4net.Layout.PatternLayout">
      <conversionPattern value="%date [%thread] %-5level %logger - %message%newline" />
    </layout>
  </appender>
  <root>
   <level value="ERROR" />
    <appender-ref ref="FileAppender" />
  </root>
</log4net>

private static readonly ILog log = LogManager.GetLogger(typeof(MainWindow));

public MainWindow()
{
    InitializeComponent();
    XmlConfigurator.Configure();
}

private void Button_Click(object sender, RoutedEventArgs e)
{
    try
    {
        // 执行可能会抛出异常的代码
    }
    catch (Exception ex)
    {
        log.Error("发生错误", ex);
    }
}

 <trace autoflush="true">
   <listeners>
      <add name="textWriterTraceListener" type="System.Diagnostics.TextWriterTraceListener" initializeData="log.txt" />
    </listeners>
  </trace>
</system.diagnostics>

private void Button_Click(object sender, RoutedEventArgs e)
{
    try
    {
        // 执行可能会抛出异常的代码
    }
    catch (Exception ex)
    {
        Trace.TraceError("发生错误: {0}", ex.ToString());
    }
}