.NET (Core and Framework)

Imports System.Security
Imports System.Threading
Imports System.Environment
Imports System.Security.Permissions

Public Class EventLogService

    '''-----------------------------------------------------------------------------
    ''' <summary>
    '''      Error message to be thrown if access is denied.
    ''' </summary>
    '''-----------------------------------------------------------------------------
    Private Const EVENTLOG_DENIED As String = "The event source {0} does not exist and cannot be created with the current permissions."

    '''-----------------------------------------------------------------------------
    ''' <summary>
    '''     Publicly exposed method to create event log entries.
    ''' </summary>
    ''' <param name="text">The text of the log to create.</param>
    ''' <remarks>
    '''     This attempts to create an entry in the WestwoodForster event log
    '''     using the current AppDomain Friendly name as the event source name.
    '''     If this cannot be done for any reason then the entry will be created
    '''     as an 'Application Error' in the Application event log.
    '''     Additionaly a check is performed so that is event logging is not supported,
    '''     such as on Windows 98, no action is performed.
    ''' </remarks>
    ''' <history>
    ''' 	[mjackson] 	19/07/2004	Created
    ''' </history>
    '''-----------------------------------------------------------------------------
    Public Sub CreateEntry(ByVal text As String)

        Dim eventlogPermission As New System.Diagnostics.EventLogPermission(PermissionState.Unrestricted)
        eventlogPermission.Assert()

        Try
            Me.writeEventLogEntry(text)
        Catch ex As PlatformNotSupportedException
        End Try

        eventlogPermission.RevertAssert()

    End Sub

    '''-----------------------------------------------------------------------------
    ''' <summary>
    '''     Internal method to write to event log.
    ''' </summary>
    ''' <param name="text">Message to log.</param>
    ''' <remarks></remarks>
    ''' <history>
    ''' 	[mjackson] 	19/07/2004	Created
    ''' </history>
    '''-----------------------------------------------------------------------------
    Private Sub writeEventLogEntry(ByVal text As String)

        Dim eventsource As String
        eventsource = AppDomain.CurrentDomain.FriendlyName

        Me.validateEventSource(eventsource)

        Try
            EventLog.WriteEntry(eventsource, text, EventLogEntryType.Error, 1000)
        Catch e As SecurityException
            Throw New SecurityException(String.Format(EVENTLOG_DENIED, AppDomain.CurrentDomain.FriendlyName), e)
        End Try

    End Sub

    '''-----------------------------------------------------------------------------
    ''' <summary>
    '''     Internal method to validate or create event sources.
    ''' </summary>
    ''' <param name="eventSource">The name of the event source to create.</param>
    ''' <remarks>
    '''     Defaults to 'Application error' if could not be created.
    ''' </remarks>
    ''' <history>
    ''' 	[mjackson] 	19/07/2004	Created
    ''' </history>
    '''-----------------------------------------------------------------------------
    Private Sub validateEventSource(ByRef eventSource As String)

        Try
            If Not EventLog.SourceExists(eventSource) Then
                EventLog.CreateEventSource(eventSource, "CustomEventLog")
            End If
        Catch e As SecurityException
            eventSource = "Application Error"
        End Try

    End Sub

End Class

Public Overloads Shared Sub WriteMessage(ByVal message As String, ByVal source As String, ByVal log As String)

    Dim password As String = "****"
    Dim username As String = "****"

    Dim tokenHandle As IntPtr = IntPtr.Zero
    Dim returnValue As Boolean = LogonUser(username, System.Environment.MachineName, password, 2, 0, tokenHandle)

    Dim impersonatedUser As WindowsImpersonationContext = WindowsIdentity.Impersonate(tokenHandle)

    Try
        CustomEventLog.InternalWriteMessage(message, source, log)
    Catch ex As PlatformNotSupportedException
    End Try

    impersonatedUser.Undo()

End Sub

Private Declare Auto Function LogonUser Lib "advapi32.dll" (ByVal lpszUsername As [String], _
    ByVal lpszDomain As [String], ByVal lpszPassword As [String], _
    ByVal dwLogonType As Integer, ByVal dwLogonProvider As Integer, _
    ByRef phToken As IntPtr) As Boolean