asked on

Error while executing WMI query to check whther CD inserted or not

Hi I have written code to check whether Cd inserted or not in drive using WMI wuery and VB6.

But while executing the code it throwing an error in while entering into 'For each' loop i.e Runtime error '-21456793':Automation error.

Can any one please help me to find out the solution for this.

Private Sub Command1_Click()
Dim strComputer
Dim objWMIService
Dim colItems
Dim objItem

strComputer = "."
Set objWMIService = GetObject("winmgmts:\\" & strComputer & "\root\cimv2")
Set colItems = objWMIService.ExecQuery("Select * from __InstanceModificationEvent Within 1 Where TargetInstance ISA 'Win32_CDROMDrive' and TargetInstance.MediaLoaded = True and PreviousInstance.MediaLoaded = False ")
For Each objItem In colItems
MsgBox "Device ID: " & objItem.DeviceID
MsgBox "Media Loaded: " & objItem.MediaLoaded
Next
End Sub

Thanks in advance

ASKER CERTIFIED SOLUTION

Psy053

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RobSampson

Also, as for the cause of your error, when you query an InstanceModificationEvent you can't use the For Each loop the way you have. You need to use the iteration structure as shown here:
http://blogs.technet.com/b/heyscriptingguy/archive/2007/04/20/how-can-i-write-a-script-that-increments-a-counter-each-time-a-log-file-is-updated.aspx

Regards,

Rob.

sandeepsangshetty

ASKER

Hi RobSampson,
After going through the link I modified my code as below but that doesn't worked fine.
Its throwing an error saying that " Runtime Error :438: Object doesn't support this property or method"

What changes need to make to run this.

Private Sub Command1_Click()
Dim strComputer
Dim objWMIService
Dim colItems
Dim objItem

strComputer = "."
Set objWMIService = GetObject("winmgmts:\\" & strComputer & "\root\cimv2")
Set colItems = objWMIService.ExecQuery("Select * from __InstanceModificationEvent Within 1 Where TargetInstance ISA 'Win32_CDROMDrive' and TargetInstance.MediaLoaded = True and PreviousInstance.MediaLoaded = False ")

Do
Set objItem = colItems.NextEvent
If colItems <> 0 Then
MsgBox "Device ID: " & objItem.DeviceID
MsgBox "Media Loaded: " & objItem.MediaLoaded
End If
Loop

End Sub

Regards,
Sandeep

sandeepsangshetty

ASKER

Thanks for ur reply

I tried to Execute ur code but same automation error getting .

RobSampson

Hi, the latest code you have is fine, except you need to change this bit:
objWMIService.ExecQuery
to this
objWMIService.ExecNotificationQuery

Regards,

Rob.