[轉載] NLog Variables

轉載自：當條件等于不作業時.net核心Nlog過濾器

我必須從我的啟動類傳遞變數值

1. LogManager.Configuration.Variables["environment"] = "Development"; 

LogManager.Configuration.Variables["environment"] = "Development";

我在我的 nlog.config 檔案中添加了以下過濾器

1. <rules> 
2.    <logger name="*" minlevel="Error" writeTo="logfile"> 
3.        <filters> 
4.            <when condition="equals('${var:environment}', 'Development')" action="Ignore" /> 
5.        </filters> 
6.    </logger> 
7. </rules> 

<rules>
    <logger name="*" minlevel="Error" writeTo="logfile">
        <filters>
            <when condition="equals('${var:environment}', 'Development')" action="Ignore" />
        </filters>
    </logger>
</rules>

即使我將值作為 Development 傳遞，該訊息仍會被記錄而不是忽略。

但是，當我對它的作業值進行硬編碼時

您在 NLog中發現了一個錯誤，但如果您這樣做，它應該可以作業（也會更快）：

1. <rules> 
2.    <logger name="*" minlevel="Error" writeTo="logfile"> 
3.        <filters defaultAction='log'> 
4.            <when condition="'${var:environment}' == 'Development'" action="Ignore" /> 
5.        </filters> 
6.    </logger> 
7. </rules> 

<rules>
    <logger name="*" minlevel="Error" writeTo="logfile">
        <filters defaultAction='log'>
            <when condition="'${var:environment}' == 'Development'" action="Ignore" />
        </filters>
    </logger>
</rules>

您也可以用 minLevel="${var:EnvironmentMinLevel:whenEmpty=Error}" 處理，這比 <filters> 快得多

1. <rules> 
2.    <logger name="*" minlevel="${var:EnvironmentMinLevel:whenEmpty=Error}" writeTo="logfile" /> 
3. </rules> 

<rules>
    <logger name="*" minlevel="${var:EnvironmentMinLevel:whenEmpty=Error}" writeTo="logfile" />
</rules>

設定 Variables 要記得呼叫 Reconfig，或者在 config 中設定 autoReload="true"

1. NLog.LogManager.Configuration.Variables["EnvironmentMinLevel"] = "Off"; 
2. NLog.LogManager.ReconfigExistingLoggers(); 

NLog.LogManager.Configuration.Variables["EnvironmentMinLevel"] = "Off";
NLog.LogManager.ReconfigExistingLoggers();

另請參閱 https://github.com/NLog/NLog/wiki/Filtering-log-messages#semi-dynamic-routing-rules