Generic WMI Coding Techniques using VB.Net

Category:

C#, VB.NET, ASP.NET

Type:

Snippets

Difficulty:

Advanced

Author:

Anonymous

Version Compatibility: Visual Basic.NET

More information:

This code snippet shows a technique of passing multiple WMI requests into generic WMI processing code. By passing in different classes and parameters to a generic method, the code is easy to maintain and reuse. For example in the two separate calls to processMetrics the below example targets two different WMI classes. The code can be easily extended to map to any number of different WMI classes.

Instructions: Copy the declarations and code below and paste directly into your VB project.

Declarations:
Imports System.Management

Code:

'NETFramework_NETCLRLoading 
processMetrics(strTarget, _ 
    "Win32_PerfRawData_NETFramework_NETCLRLoading", _ 
    "BytesinLoaderHeap", "Currentappdomains", _ 
    "CurrentAssemblies", "CurrentClassesLoaded", _ 
    "TotalAppdomains", _ 
    "TotalAssemblies", "TotalNumberofLoadFailures")

'NETFramework_NETCLRRemoting 
processMetrics(strTarget, _ 
    "Win32_PerfRawData_NETFramework_NETCLRRemoting", _ 
    "Channels", "ContextBoundClassesLoaded", _ 
    "ContextProxies", "Contexts", _ 
    "TotalRemoteCalls")

Public Sub processMetrics(ByVal strTarget As String, ByVal strClass As String, ByVal ParamArray strArray() As String) 
Dim oFile As System.IO.File 
Dim oWrite As System.IO.StreamWriter 
Dim I As Integer

Try 
Dim strSQL As String = "Select * from " & strClass 
Dim oQuery As New System.Management.ObjectQuery(strSQL)

Dim oScope As New System.Management.ManagementScope("\\" & _ 
strTarget & "\root\cimv2")

Dim oSearcher As New System.Management.ManagementObjectSearcher(oScope, oQuery)

Dim oService As System.Management.ManagementObject

oWrite = oFile.AppendText("C:\WMI\" & strTarget & ".xls")

For Each oService In oSearcher.Get() 
  For I = 0 To UBound(strArray) 
    oWrite.WriteLine(strTarget & vbTab & Date.Today & vbTab &  TimeOfDay & vbTab & _ 
    strClass & vbTab & oService("Name") & vbTab & _ 
    strArray(I) & vbTab & oService(strArray(I)).ToString) 
  Next 
Next 
oWrite.Close() 
Catch errProcessMetrics As Exception 
  MsgBox("Error in processMetrics for class: " & strClass & "  with error: " & errProcessMetrics.Message) 
  oWrite.Close()
End Try 
End Sub

Public Sub setTitles(ByVal strTarget As String) 
Dim oFile As System.IO.File 
Dim oWrite As System.IO.StreamWriter

Try 
  oWrite = oFile.AppendText("C:\WMI\" & strTarget & ".xls") 
  oWrite.WriteLine("Server" & vbTab & "DateInterval" & vbTab   & "TimeInterval" & vbTab & _ 
  "MetricCategory" & vbTab & "Name" & vbTab & "MetricName" &   vbTab & "MetricValue") 
  oWrite.Close() 
Catch errSetTitles As Exception 
  MsgBox("Error in setTitles: " & errSetTitles.Message) 
  oWrite.Close()
End Try 
End Sub