[C#]NuGet - Info and Configuration-API for NLog

• 安裝 Nlog

• 專案檔中會有下列兩個檔案
• NLog.config
• NLog.xsd
• NLog.config 資訊
• targets
1. 定義 Log 要存放的 type 為何
2. 定義 Log 內容格式
3. 可設定多組 target 
• rules
1. 定義各種 Level 的 Log 處理方式
2. 依據各種 Level 定義使用哪個 target 存放資料
3. 可設定多組 rules

• Targets [設定] 寫入目標
• Code

< targets>
    /*
    add your targets here
    See https://github.com/nlog/NLog/wiki/Targets for possible targets.
    See https://github.com/nlog/NLog/wiki/Layout-Renderers for the possible layout renderers.
    (1)
    NLog package (xsi:type="File")
    https://github.com/NLog/NLog/wiki/Targets
    ColoredConsole - Writes log messages to the console with customizable coloring.
    Console - Writes log messages to the console.
    Database - Writes log messages to the database using an ADO.NET provider.
    EventLog - Writes log message to the Event Log.
    File - Writes log messages to one or more files.
    Mail - Sends log messages by email using SMTP protocol.
    NLogViewer - Sends log messages to the remote instance of NLog Viewer.
    OutputDebugString - Outputs log messages through the OutputDebugString() Win32 API.

    (2)
    name – target name

    (3)
    Layout Renderers (layout="${longdate} ${uppercase:${level}} ${message}")
    https://github.com/NLog/NLog/wiki/Layout-renderers
    ${basedir}–應用程式所在的資料庫
    ${callsite}–日誌來源的類別名稱、方法名稱和來源資訊
    ${date}–目前日期和時間
    ${onexception}–例外的訊息
    ${level}–日誌的級別
    ${logger}–日誌的來源
    ${longdate}–長日期格式 yyyy-MM-dd HH:mm:ss.mmm
    ${machinename}–電腦名稱
    ${message}–日誌的內容
    ${newline}–換行符號
    ${shortdate}–短日期格式 yyyy-MM-dd
    ${stacktrace}–呼叫堆疊資訊
    ${windows-identity}–登入帳號
    */

    /* Sample Write events to a file with the date in the filename.*/
    < target
      xsi:type="File"
      name="f"
      fileName="${basedir}/logs/${shortdate}.log"
      layout="${longdate} ${uppercase:${level}} ${message}" />

  < /targets>
C#

• Rules [設定] 紀錄規則
• Code

< rules>
  /*
  add your logging rules here

  Log element (minlevel="Debug")
  NLog 可以使用的屬性
  https://github.com/NLog/NLog/wiki/Configuration-file#Rules
  (1)
  name–日誌來源的名稱(允許使用通配符號*)

  (2)
  level–設定符合該規則的特定級別
  levels–設定符合該規則的級別列表，用逗號分隔
  minlevel–設定符合該規則的最低級別
  maxlevel–設定符合該規則的最高級別
  (2*)
  The level related keywords are processed in the following order:
  1. level
  2. levels
  3. minlevel and maxlevel (minimum and maximum level keywords have the same priority)
  4. No keyword (All levels are logged)
  (2**)
  log level (minlevel="Debug")
  NLog 日誌級別分為六個等級，方便對於不同情境制訂出合適級別輸出
  https://github.com/NLog/NLog/wiki/Configuration-file#log-levels
  Fatal–致命錯誤的訊息，通常會造成應用程式無法執行
  Error–一般錯誤的訊息，一般就是try catch到的Exception
  Info–用來提示用的訊息，例如使用者登出入，交易參數資料
  Warn–用來警告用的訊息，例如執行時間超出預期，連線數接近上限
  Debug–用來除錯用的詳細訊息，比Trace用的少一點，一般也只用在開發環境
  Trace–大量而詳細的訊息，一般只用在開發環境

  (3)
  writeTo–設定符合該規則的日誌要寫入的target列表，用逗號分隔
  final–設定符合該規則的條件為最後一個規則，後面的規則不再檢查
  enabled–Disabled rules are ignored
  */

  /* Write all events with minimal level of Debug (So Debug, Info, Warn, Error and Fatal, but not Trace)  to "f" */
  < logger name="*" minlevel="Debug" writeTo="f" />

< /rules>
C#

• Using  NLog
• Code

// Using NLog.config Info
NLog.Logger logger = LogManager.GetCurrentClassLogger();
logger.Info("Info Lyndon");
logger.Error("Error Demo");
C#

• Configuration-API
• 如果不想使用 NLog.config 可使用 Configuration-API
• Code

// Sample: https://github.com/nlog/NLog/wiki/Configuration-API
// Step 1. Create configuration object
LoggingConfiguration config = new LoggingConfiguration();

// Step 2. Create targets and add them to the configuration
FileTarget fileTarget = new FileTarget();
config.AddTarget("file", fileTarget);

// Step 3. Set target properties
fileTarget.FileName = "${basedir}/logs/${shortdate}Demo.log";
fileTarget.Layout = "${longdate} | ${callsite} | ${uppercase:${level}} | ${message}";

// Step 4. Define rules
LoggingRule rule = new LoggingRule("*", LogLevel.Debug, fileTarget);
config.LoggingRules.Add(rule);

// Step 5. Activate the configuration
LogManager.Configuration = config;

// Example usage
Logger logger = LogManager.GetLogger("DemoExample");
logger.Trace("trace log message");
logger.Debug("debug log message");
logger.Info("info log message");
logger.Warn("warn log message");
logger.Error("error log message");
logger.Fatal("fatal log message");
C#

• 此方法會將原本的 config 資訊給取代掉，因此原本 config 資訊將不動作
• Add Target and Rule
• 此方法可以延用原本的 config ，並加上新增加的 Target 與 Rule
• Code

// Sample: https://github.com/nlog/NLog/wiki/Configuration-API
// Step 1. Create configuration object
//LoggingConfiguration config = new LoggingConfiguration();

// Step 2. Create targets and add them to the configuration
FileTarget fileTarget = new FileTarget();
LogManager.Configuration.AddTarget("file", fileTarget);

// Step 3. Set target properties
fileTarget.FileName = "${basedir}/logs/${shortdate}Demo.log";
fileTarget.Layout = "${longdate} | ${callsite} | ${uppercase:${level}} | ${message}";

// Step 4. Define rules
LoggingRule rule = new LoggingRule("NLogAPConfigILib", LogLevel.Debug, fileTarget);
//config.LoggingRules.Add(rule);
LogManager.Configuration.LoggingRules.Add(rule);
// *** Reload
LogManager.Configuration.Reload();

// Step 5. Activate the configuration
//LogManager.Configuration = config;

// Example usage
Logger logger = LogManager.GetLogger("NLogAPConfigILib");
logger.Trace("trace log message");
logger.Debug("debug log message");
logger.Info("info log message");
logger.Warn("warn log message");
logger.Error("error log message");
logger.Fatal("fatal log message");
C#

• 加入 Target 與 Rules，一定要呼叫 LogManager.Configuration.Reload()
• variable [變數] 文字樣板
• 當有相同的 layout，可將參數設定至此

• Code (Before)

< variable name="myvar" value="myvalue"/>

< targets>
  < target
    xsi:type="File"
    name="f"
    fileName="${basedir}/logs/${shortdate}.log"
    layout="${longdate} ${uppercase:${level}} ${message}" />
< /targets>

< rules>
  < logger name="NLogLib" minlevel="Debug" writeTo="f" />
< /rules>
C#

• Code (After)

< variable name="DemoLayout" value="${longdate} ${uppercase:${level}} ${message}"/>

< targets>
  < target
    xsi:type="File"
    name="f"
    fileName="${basedir}/logs/${shortdate}.log"
    layout="${DemoLayout}" />
< /targets>

< rules>
  < logger name="NLogLib" minlevel="Debug" writeTo="f" />
< /rules>
C#

• Ref:
• https://dotblogs.com.tw/wasichris/2015/02/27/150582
• https://stackoverflow.com/questions/7471490/add-enable-and-disable-nlog-loggers-programmatically
• http://blog.developer.idv.tw/2012/12/nlog-rules.html
• https://xianlee.gitbooks.io/csharp/content/nlog/index.html
• http://www.jianshu.com/p/0059a69da89e
• https://jeffprogrammer.wordpress.com/2015/12/13/asp-net-mvc-%E7%B0%A1%E6%98%93%E4%BD%BF%E7%94%A8-nlog-%E6%8D%95%E6%8D%89%E7%95%B0%E5%B8%B8%E7%8B%80%E6%B3%81/
• https://dotblogs.com.tw/jwpl102216/2017/03/26/090338
• http://ithelp.ithome.com.tw/articles/10138479
• http://blog.darkthread.net/post-2016-05-16-nlog-trouble-shooting.aspx
• https://xianlee.gitbooks.io/csharp/content/nlog/index.html
• http://ithelp.ithome.com.tw/articles/10138479
• https://dotblogs.com.tw/jwpl102216/2017/03/26/090338
• https://jeffprogrammer.wordpress.com/2015/12/13/asp-net-mvc-%E7%B0%A1%E6%98%93%E4%BD%BF%E7%94%A8-nlog-%E6%8D%95%E6%8D%89%E7%95%B0%E5%B8%B8%E7%8B%80%E6%B3%81/