Q216146: HOWTO:Get Number of Windows NT Event Log Records in Visual Basic

Article: Q216146
Product(s): Microsoft Visual Basic for Windows
Version(s): WINDOWS:4.0,5.0,6.0
Operating System(s): 
Keyword(s): kbAPI kbEventLog kbOSWinNT kbSDKWin32 kbVBp kbVBp400 kbVBp500 kbVBp600 kbGrpDSVB kbDSup
Last Modified: 11-JAN-2001

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The information in this article applies to:

- Microsoft Visual Basic Standard Edition, 32-bit, for Windows, version 4.0 
- Microsoft Visual Basic Professional Edition, 32-bit, for Windows, version 4.0 
- Microsoft Visual Basic Enterprise Edition, 32-bit, for Windows, version 4.0 
- Microsoft Visual Basic Learning Edition for Windows, versions 5.0, 6.0 
- Microsoft Visual Basic Professional Edition for Windows, versions 5.0, 6.0 
- Microsoft Visual Basic Enterprise Edition for Windows, versions 5.0, 6.0 
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SUMMARY
=======

Event logging in Windows provides a standard, centralized way for Windows and
other applications to record important software and hardware events. Event
logging also supplies a standard user interface for viewing the logs and a
programming interface for examining the logs.

This article illustrates how to get the number of records contained within a
specified Microsoft Windows 2000 or Windows NT Event Log with Visual Basic
version 4.0 and later. This can be done using the GetNumberOfEventLogRecords API
call. While Visual Basic 5.0 and later versions have built in functionality for
event logging, they do not provide the functionality that the Win32 API does.

MORE INFORMATION
================

The following example shows how to get the number of event log records in the
local Application Event Log.

Step by Step Example:

1. Create a new Visual Basic project. Form1 is created by default.

2. Add a command button to Form1. Change the name of the command button to
  cmdGetNumberOfEventLogRecords.

3. Add the following code to the Form1 code window:

  Private Declare Function GetNumberOfEventLogRecords Lib "advapi32.dll" ( _
      ByVal hEventLog As Long, _
      NumberOfRecords As Long) _
      As Long

  Private Declare Function CloseEventLog Lib "advapi32.dll" ( _
      ByVal hEventLog As Long) _
      As Long

  Private Declare Function OpenEventLog Lib "advapi32.dll" Alias "OpenEventLogA" ( _
      ByVal lpUNCServerName As String, _
      ByVal lpSourceName As String) _
      As Long

  Private Sub cmdGetNumberOfEventLogRecords_Click()
      Dim hEventLog As Long
      Dim lEventLogRecordCount As Long
      Dim lretv As Long
      
      hEventLog = OpenEventLog(vbNullString, "Application")
      If hEventLog = 0 Then
           Debug.Print "OpenEventLog Failed"
           Exit Sub
      End If
      
      lretv = GetNumberOfEventLogRecords(hEventLog, lEventLogRecordCount)
      If lretv = 0 Then
           Debug.Print GetNumberOfEventLogRecords Failed"
           Exit Sub
      Else
          Debug.Print "Number of records: " & CStr(lEventLogRecordCount)
      End If
                  
      lretv = CloseEventLog(hEventLog)
      If lretv = 0 Then
           Debug.Print "CloseEventLog Failed"
           Exit Sub
      End If

  End Sub

4. Press F5 to run the project, and then and click the
  cmdGetNumberOfEventLogRecords command button. A message box should appear
  that displays the number of records.

REFERENCES
==========

For additional information on event logging from Visual Basic, click the article
numbers below to view the articles in the Microsoft Knowledge Base:

  Q154576 HOWTO: Write to the Windows NT Event Log from Visual Basic

  Q161306 INFO: App.LogEvent Only Logs in Compiled Applications

  Q184747 INFO: Event Logging in Visual Basic

  Q216097 HOWTO: Clear the NT Event Log in Visual Basic

  Q216089 HOWTO: Backup the NT Event Log in Visual Basic

Additional query words:

======================================================================
Keywords          : kbAPI kbEventLog kbOSWinNT kbSDKWin32 kbVBp kbVBp400 kbVBp500 kbVBp600 kbGrpDSVB kbDSupport kbCodeSnippet 
Technology        : kbVBSearch kbAudDeveloper kbZNotKeyword6 kbZNotKeyword2 kbVB500Search kbVB600Search kbVBA500 kbVBA600 kbVB500 kbVB600 kbVB400Search kbVB400
Version           : WINDOWS:4.0,5.0,6.0
Issue type        : kbhowto

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