如何使用 Enterprise Library Logging 仅编写消息以调试输出？

Question

我想使用 EntLib Logging 实现日志记录，并为“调试”类别连接两个 TraceListener。一个将这些消息写入文件，另一个将它们输出到系统跟踪输出，就像 Debug.Write 一样（这样我就可以使用 Sysinternals DbgView 监视它们），但我找不到如何使用格式化程序设置第二个侦听器我需要。我真正需要的只是消息，但它会输出一大堆东西，比如 EventId、Priority 等。我该如何删掉所有这些东西？

Answer 1

我在 MSDN 上找到了一个不错的演练：Creating a Custom Trace Listener

它完全符合我的需要。这是我最终得到的完整代码：

using System;
using System.Diagnostics;
using Microsoft.Practices.EnterpriseLibrary.Common.Configuration;
using Microsoft.Practices.EnterpriseLibrary.Logging;
using Microsoft.Practices.EnterpriseLibrary.Logging.Configuration;
using Microsoft.Practices.EnterpriseLibrary.Logging.TraceListeners;

namespace Common.Utils
{
    [ConfigurationElementType(typeof(CustomTraceListenerData))]
    public class FormattedDebugWriterTraceListener : CustomTraceListener
    {
        public override void TraceData(TraceEventCache eventCache, string source, TraceEventType eventType, int id, object data)
        {
            if (data is LogEntry && this.Formatter != null)
            {
                this.WriteLine(this.Formatter.Format(data as LogEntry));
            }
            else
            {
                this.WriteLine(data.ToString());
            }
        }

        public override void Write(string message)
        {
            Debug.Write(message);
        }

        public override void WriteLine(string message)
        {
            Debug.WriteLine(message);
        }

    }
}

配置文件：

<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <configSections>
    <section name="loggingConfiguration" type="Microsoft.Practices.EnterpriseLibrary.Logging.Configuration.LoggingSettings, Microsoft.Practices.EnterpriseLibrary.Logging, Version=3.1.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" />
    <section name="dataConfiguration" type="Microsoft.Practices.EnterpriseLibrary.Data.Configuration.DatabaseSettings, Microsoft.Practices.EnterpriseLibrary.Data, Version=3.1.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" />
  </configSections>
  <loggingConfiguration name="Logging Application Block" tracingEnabled="true"
    defaultCategory="General" logWarningsWhenNoCategoriesMatch="true">
    <listeners>
      <add listenerDataType="Microsoft.Practices.EnterpriseLibrary.Logging.Configuration.CustomTraceListenerData, Microsoft.Practices.EnterpriseLibrary.Logging, Version=3.1.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a"
        traceOutputOptions="None" type="Common.Utils.FormattedDebugWriterTraceListener, Common.Utils"
        name="FormattedDebugWriterTraceListener" initializeData="" formatter="SimpleMessageFormatter" />
      <add fileName="log\Debugging.log" rollSizeKB="0" timeStampPattern="yyyy-MM-dd"
        rollFileExistsBehavior="Overwrite" rollInterval="Week" formatter="GeneralTextFormatter"
        header="----------------------------------------" footer="----------------------------------------"
        listenerDataType="Microsoft.Practices.EnterpriseLibrary.Logging.Configuration.RollingFlatFileTraceListenerData, Microsoft.Practices.EnterpriseLibrary.Logging, Version=3.1.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a"
        traceOutputOptions="None" type="Microsoft.Practices.EnterpriseLibrary.Logging.TraceListeners.RollingFlatFileTraceListener, Microsoft.Practices.EnterpriseLibrary.Logging, Version=3.1.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a"
        name="RollingFlatFileTraceListener" />
    </listeners>
    <formatters>
      <add template="{message}&#xD;&#xA;" type="Microsoft.Practices.EnterpriseLibrary.Logging.Formatters.TextFormatter, Microsoft.Practices.EnterpriseLibrary.Logging, Version=3.1.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a"
        name="SimpleMessageFormatter" />
      <add template="Timestamp: {timestamp}&#xD;&#xA;Message: {message}&#xD;&#xA;Category: {category}&#xD;&#xA;Priority: {priority}&#xD;&#xA;EventId: {eventid}&#xD;&#xA;Severity: {severity}&#xD;&#xA;Title:{title}&#xD;&#xA;Machine: {machine}&#xD;&#xA;Application Domain: {appDomain}&#xD;&#xA;Process Id: {processId}&#xD;&#xA;Process Name: {processName}&#xD;&#xA;Win32 Thread Id: {win32ThreadId}&#xD;&#xA;Thread Name: {threadName}&#xD;&#xA;Extended Properties: {dictionary({key} - {value}&#xD;&#xA;)}"
        type="Microsoft.Practices.EnterpriseLibrary.Logging.Formatters.TextFormatter, Microsoft.Practices.EnterpriseLibrary.Logging, Version=3.1.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a"
        name="GeneralTextFormatter" />
    </formatters>
    <categorySources>
      <add switchValue="All" name="Debugging">
        <listeners>
          <add name="FormattedDebugWriterTraceListener" />
          <add name="RollingFlatFileTraceListener" />
        </listeners>
      </add>
      <add switchValue="All" name="General" />
    </categorySources>
    <specialSources>
      <allEvents switchValue="All" name="All Events" />
      <notProcessed switchValue="All" name="Unprocessed Category" />
      <errors switchValue="All" name="Logging Errors &amp; Warnings" />
    </specialSources>
  </loggingConfiguration>
</configuration>

用法是这样的：

Debug.Write("Debug.Write test");
Logger.Write("EntLib test", "Debugging");

两者都以调试输出结束，可以通过 DbgView 轻松跟踪。

Answer 2

在您的应用程序的 EntLib 配置中，您指定要使用的 Formatter。默认格式化程序包括所有这些信息。要删除您不感兴趣的信息，请从您当前使用的 TextFormatter 中删除它们，或者创建一个包含所需字段的新文本格式化程序，然后更改“调试”以使用您的新格式化程序。