NLog: can’t write to event log

event-logloggingnlog

I can't write to the event log with NLog. I've been able to write to the console and to a file. I've turned on exceptions in NLog and am receiving no feedback from NLog.

Here is my NLog.config:

<?xml version="1.0" encoding="utf-8" ?>
<nlog xmlns="http://www.nlog-project.org/schemas/NLog.xsd"
      xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
      throwExceptions="true">
    <targets>
        <target name="console" xsi:type="Console" layout="${message}" />
        <target xsi:type="EventLog" name="eventlog" layout="${message}" log="Application" source="aaaTest"/>
        <target xsi:type="File" fileName="log.txt" name="file"/>
    </targets>

    <rules>
        <logger name="*" minlevel="Debug" writeTo="eventlog,console,file" />
    </rules>
</nlog>

In Event Viewer, I am looking at "Event Viewer (Local)" > "Windows Logs" > "Application". However, I see no instances of "aaaTest" (my defined source) in the log.

Best Answer

From nlog forum post

To be able to write to the EventLog an application must be registered as an event source. If you run VS as admin this happens automatically. If you create an installer and install your application it gets registered.

To register an app manually as event source I use the following script:

Set Args = WScript.Arguments
If Args.Count < 1 then
    WScript.Echo "USAGE: CreateEventSource.vbs <EventSourceName>"
    WScript.Quit
End If
EventSourceName = Args(0)

Set WshShell = WScript.CreateObject("WScript.Shell")

'Create event source
KeyName = "HKLM\SYSTEM\CurrentControlSet\Services\Eventlog\Application\" & EventSourceName & "\EventMessageFile"
'Change path to .NET Framework version used
WshShell.RegWrite KeyName,"%windir%\Microsoft.NET\Framework64\v2.0.50727\EventLogMessages.dll", "REG_EXPAND_SZ"
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