无配置文件使用Enterprise Library Logging Application Block 4.1

          以前曾经有同事问我，如何使用直接使用Enterprise Library Logging Application Block，而不需要写任何配置文件。我的回答是可以的。是的，今天让我们实现下。
我们知道能常EntLib需要读取config中配置节信息，那我们可以在Code里传送相应的信息给它，看以下的代码:

    public class LoggingConfigurationSource : IConfigurationSource
    {
        #region Public Methods

        public void Add(IConfigurationParameter saveParameter, string sectionName, ConfigurationSection configurationSection)
        {
        }

        public void AddSectionChangeHandler(string sectionName, ConfigurationChangedEventHandler handler)
        {
        }

        public ConfigurationSection GetSection(string sectionName)
        {
            if (sectionName.Equals("loggingConfiguration", StringComparison.CurrentCulture))
            {
                // Logging configuration
                var loggingSettings = new LoggingSettings();
                loggingSettings.DefaultCategory = "General";
                loggingSettings.TracingEnabled = true;
                loggingSettings.LogWarningWhenNoCategoriesMatch = true;

                // Listners
                var listenerReference = new TraceListenerReferenceData();
                listenerReference.Name = "RollingFiletLogListener";

                var rollingFlatFileTraceListenerData = new RollingFlatFileTraceListenerData();
                rollingFlatFileTraceListenerData.FileName = "mylog.txt";
                rollingFlatFileTraceListenerData.RollSizeKB = 1024;
                rollingFlatFileTraceListenerData.RollInterval = RollInterval.Day;
                rollingFlatFileTraceListenerData.RollFileExistsBehavior = RollFileExistsBehavior.Increment;
                rollingFlatFileTraceListenerData.Type = typeof (RollingFlatFileTraceListener);
                rollingFlatFileTraceListenerData.ListenerDataType = typeof (RollingFlatFileTraceListenerData);
                rollingFlatFileTraceListenerData.Filter = SourceLevels.All;
                rollingFlatFileTraceListenerData.TraceOutputOptions = TraceOptions.None;
                rollingFlatFileTraceListenerData.Name = "RollingFiletLogListener";
                rollingFlatFileTraceListenerData.Header = "---------------Header---------------";
                rollingFlatFileTraceListenerData.Footer = "-----------------Footer----------------";
                loggingSettings.TraceListeners.Add(rollingFlatFileTraceListenerData);


                // Formatters
                var template = new StringBuilder();
                template.AppendLine("Timestamp: {timestamp}");
                template.AppendLine("Message: {message}");
                template.AppendLine("Category: {category}");
                template.AppendLine("Priority: {priority}");
                template.AppendLine("EventId: {eventid}");
                template.AppendLine("Severity: {severity}");
                template.AppendLine("Title:{title}");
                template.AppendLine("Machine: {machine}");
                template.AppendLine("Application Domain: {appDomain}");
                template.AppendLine("Process    {processId}");
                template.AppendLine("Process Name: {processName}");
                template.AppendLine("Win32 Thread    {win32ThreadId}");
                template.AppendLine("Thread Name: {threadName}");
                template.AppendLine("Extended Properties: {dictionary({key} - {value})}");
                var formatter = new TextFormatterData();
                formatter.Name = "TextFormatter";
                formatter.Type = typeof (TextFormatter);
                formatter.Template = template.ToString();
                loggingSettings.Formatters.Add(formatter);

                // Category Sources
                var exceptionsSource = new TraceSourceData();
                exceptionsSource.TraceListeners.Add(listenerReference);
                exceptionsSource.Name = "Exceptions";
                exceptionsSource.DefaultLevel = SourceLevels.All;
                loggingSettings.TraceSources.Add(exceptionsSource);
                var traceSource = new TraceSourceData();
                traceSource.TraceListeners.Add(listenerReference);
                traceSource.Name = "Trace";
                traceSource.DefaultLevel = SourceLevels.All;
                loggingSettings.TraceSources.Add(traceSource);
                var generalSource = new TraceSourceData();
                generalSource.TraceListeners.Add(listenerReference);
                generalSource.Name = "General";
                generalSource.DefaultLevel = SourceLevels.All;
                loggingSettings.TraceSources.Add(generalSource);

                // Special Sources
                loggingSettings.SpecialTraceSources.AllEventsTraceSource.Name = "AllEvents";
                loggingSettings.SpecialTraceSources.AllEventsTraceSource.DefaultLevel = SourceLevels.All;
                loggingSettings.SpecialTraceSources.NotProcessedTraceSource.Name = "NotProcessed";
                loggingSettings.SpecialTraceSources.NotProcessedTraceSource.DefaultLevel = SourceLevels.All;
                loggingSettings.SpecialTraceSources.ErrorsTraceSource.Name = "LoggingErrorsAndWarnings";
                loggingSettings.SpecialTraceSources.ErrorsTraceSource.DefaultLevel = SourceLevels.All;
                loggingSettings.SpecialTraceSources.ErrorsTraceSource.TraceListeners.Clear();
                loggingSettings.SpecialTraceSources.ErrorsTraceSource.TraceListeners.Add(listenerReference);

                // Return
                return loggingSettings;
            }
            return null;
        }

        public void Remove(IConfigurationParameter removeParameter, string sectionName)
        {
        }

        public void RemoveSectionChangeHandler(string sectionName, ConfigurationChangedEventHandler handler)
        {
        }

        #endregion
    }

注意，这里我们配置是使用RollingFlatFileTraceListener，也就是写磁盘文件Logfile.你可以替换其它的Listener.从上面的Code，我们可以看出，config配置节也就是写着这些信息。
接下来建立一个Class来调用它：

    public static class LoggingHandler
    {
        #region Constants

        private readonly static string CategoryExceptions = "Exceptions";
        private readonly static int PriorityExceptions = 1000;
        private readonly static int EventIdExceptions = 1000;
        private readonly static string TitleExceptions = "Errors Log";
        private readonly static TraceEventType SeverityExceptions = TraceEventType.Error;

        #endregion

        #region Members

        private static LogWriter writer;

        #endregion

        #region Properties

        internal static LogWriter Writer
        {
            get
            {
                if (writer == null)
                {
                    writer = CreateWriter();
                }
                return writer;
            }
        }

        #endregion

        #region Public Methods

        public static void Exception(Exception ex)
        {
            // Validation
            if (ex == null)
            {
                throw new ArgumentNullException();
            }
            // Log
            WriteEntry(CategoryExceptions, TitleExceptions, ex.ToString(), PriorityExceptions, EventIdExceptions,
                       SeverityExceptions);
        }

        #endregion

        #region Private Methods

        private static void WriteEntry(string category, string title, string message, int priority, int eventId,
                                       TraceEventType severity)
        {
            var entry = new LogEntry();
            entry.Categories.Add(category);
            entry.TimeStamp = DateTime.Now;
            entry.EventId = eventId;
            entry.Message = message;
            entry.Priority = priority;
            entry.Severity = severity;
            entry.Title = title;
            Writer.Write(entry);
        }

        private static LogWriter CreateWriter()
        {
            var factory = new LogWriterFactory(new LoggingConfigurationSource());
            return factory.Create();
        }

        #endregion
    }

使用：

    [TestFixture]
    public class TestNonConfigEntLibLogger
    {
        [Test]
        public void TestWrite()
        {
            var log = new LogEntry() { Message = "This a test message", Title = "logging title" };
            LoggingHandler.Writer.Write(log);

            LoggingHandler.Exception(new Exception("This is a test exception"));

            string path = Path.Combine(Environment.CurrentDirectory + "\\mylog.txt");
            Assert.IsNotNull(path);
        }
    }

在mylog.txt文件中，我们看到以下内容：

---------------Header---------------
General Information: 0 : Timestamp: 9/24/2010 4:02:40 AM
Message: This a test message
Category: General
Priority: -1
EventId: 0
Severity: Information
Title:logging title
App Domain: domain-nunit.tdnet.dll
ProcessId: 5400
Process Name: D:\Program Files (x86)\TestDriven.NET 3\ProcessInvocation86.exe
Thread Name: TestRunnerThread
Win32 ThreadId:4636
Extended Properties:
-----------------Footer----------------
---------------Header---------------
Exceptions Error: 1000 : Timestamp: 9/24/2010 12:02:40 PM
Message: System.Exception: This is a test exception
Category: Exceptions
Priority: 1000
EventId: 1000
Severity: Error
Title:Errors Log
App Domain: domain-nunit.tdnet.dll
ProcessId: 5400
Process Name: D:\Program Files (x86)\TestDriven.NET 3\ProcessInvocation86.exe
Thread Name: TestRunnerThread
Win32 ThreadId:4636
Extended Properties:
-----------------Footer----------------

实际上做为EntLib，并不用推荐这么使用，因为这样做损失了很多优势了。我们的测试所用的Version是EntLib 4.1。希望对您开发有帮助。

作者：Petter Liu
出处：http://www.cnblogs.com/wintersun/
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该文章也同时发布在我的独立博客中-Petter Liu Blog。