(newbie warning) vb.net, stdregprov, deletekey - Invalid cast

  • Thread starter Thread starter Schroeder, AJ
  • Start date Start date
S

Schroeder, AJ

Hello,

I am trying to delete keys via WMI using VB.NET. I have used the "EnumKeys"
method before, but the "DeleteKey" method is obviously different. The error
that I get is "The specified cast is invalid" on the GetMethodParameters
line, and I have googled and there isn't much out there specifically for
what I am doing.

I am hoping to the members in these newsgroups will be able to provide me
with some advice, it would be much appreciated!

Along with my thanks, the code is below:

Enum MainRegHives

HKEY_CLASSES_ROOT = &H80000000

HKEY_CURRENT_USER = &H80000001

HKEY_LOCAL_MACHINE = &H80000002

HKEY_USERS = &H80000003

HKEY_CURRENT_CONFIG = &H80000005

End Enum


Dim strHKLM As MainRegHives
Dim objEnumDeleteKeys As System.Management.ManagementBaseObject

Dim objDeleteKeys As System.Management.ManagementObject

Dim WMIManagementClass As System.Management.ManagementClass

Dim WMIManagementScope As System.Management.ManagementScope

Try

strHKLM = MainRegHives.HKEY_LOCAL_MACHINE

WMIManagementScope = New System.Management.ManagementScope

With WMIManagementScope

..Path.Server = strServer

..Path.NamespacePath = "root\default"

..Options.EnablePrivileges = True

'.Options.Username = "AdminUser

'.Options.Password = "adminpass"

'.Options.Impersonation = ImpersonationLevel.Impersonate

' For XP compatibility

'.Options.Authentication = System.Management.AuthenticationLevel.Packet

' For 2000/NT compatibility

'.Options.Authentication = System.Management.AuthenticationLevel.Connect

End With

WMIManagementScope.Connect()

Catch ex As Exception

End Try

Try

WMIManagementClass = New System.Management.ManagementClass("StdRegProv")

With WMIManagementClass

..Scope = WMIManagementScope

End With

Catch ex As ManagementException

Console.WriteLine(("Failed to query WMI on " & strServer & ": " & ex.Message
& " Error code: " & ex.ErrorCode))

End Try

Try

objDeleteKeys = WMIManagementClass.GetMethodParameters("DeleteKey")

With objDeleteKeys

..SetPropertyValue("hDefKey", CType("&H" & Hex(strHKLM), Long))

..SetPropertyValue("sSubKeyName", strRegPath)

End With

objDeleteKeys.Delete()

Catch ex As ManagementException

Debug.WriteLine(ex.ErrorInformation)

End Try
 
Hi,

GetMethodParameters returns a ManagementBaseObject not a
ManagementObject. You can not convert a manamentbaseobject to an
managementobject.

Why not use the win32.registry classes. You can use the
registrykeys openremotebasekey to access the registry on another machine.

http://msdn.microsoft.com/library/d...n32registrykeyclassopenremotebasekeytopic.asp

Ken
------------------
Hello,

I am trying to delete keys via WMI using VB.NET. I have used the "EnumKeys"
method before, but the "DeleteKey" method is obviously different. The error
that I get is "The specified cast is invalid" on the GetMethodParameters
line, and I have googled and there isn't much out there specifically for
what I am doing.

I am hoping to the members in these newsgroups will be able to provide me
with some advice, it would be much appreciated!

Along with my thanks, the code is below:

Enum MainRegHives

HKEY_CLASSES_ROOT = &H80000000

HKEY_CURRENT_USER = &H80000001

HKEY_LOCAL_MACHINE = &H80000002

HKEY_USERS = &H80000003

HKEY_CURRENT_CONFIG = &H80000005

End Enum


Dim strHKLM As MainRegHives
Dim objEnumDeleteKeys As System.Management.ManagementBaseObject

Dim objDeleteKeys As System.Management.ManagementObject

Dim WMIManagementClass As System.Management.ManagementClass

Dim WMIManagementScope As System.Management.ManagementScope

Try

strHKLM = MainRegHives.HKEY_LOCAL_MACHINE

WMIManagementScope = New System.Management.ManagementScope

With WMIManagementScope

..Path.Server = strServer

..Path.NamespacePath = "root\default"

..Options.EnablePrivileges = True

'.Options.Username = "AdminUser

'.Options.Password = "adminpass"

'.Options.Impersonation = ImpersonationLevel.Impersonate

' For XP compatibility

'.Options.Authentication = System.Management.AuthenticationLevel.Packet

' For 2000/NT compatibility

'.Options.Authentication = System.Management.AuthenticationLevel.Connect

End With

WMIManagementScope.Connect()

Catch ex As Exception

End Try

Try

WMIManagementClass = New System.Management.ManagementClass("StdRegProv")

With WMIManagementClass

..Scope = WMIManagementScope

End With

Catch ex As ManagementException

Console.WriteLine(("Failed to query WMI on " & strServer & ": " & ex.Message
& " Error code: " & ex.ErrorCode))

End Try

Try

objDeleteKeys = WMIManagementClass.GetMethodParameters("DeleteKey")

With objDeleteKeys

..SetPropertyValue("hDefKey", CType("&H" & Hex(strHKLM), Long))

..SetPropertyValue("sSubKeyName", strRegPath)

End With

objDeleteKeys.Delete()

Catch ex As ManagementException

Debug.WriteLine(ex.ErrorInformation)

End Try
 
Hi,

I don't understand why anyone would use VB.NET for this type of
programming? I've never seen such convoluted code for such a simple
task. VB is the worst language available in .NET and is not standards based.

Forgetting the cast, can you clarify strRegPath in the code below. I
can't see where it's defined.
 
Well, everyone around here uses VB, so it was a natural choice because
of the learning curve. I agree, this code is quite convoluted (it is
even more apparent now that I am looking at C# examples), maybe I'll
cut my losses and switchover to C#. It does look WAY easier!

Anyway, strRegPath is just a parameter that I am passing from Main. Tis
just a path to the registry keys...

BTW - I have figured it out and I changed my ManagementObject to a
ManagementBaseObject and now the keys are being removed...
 
Hi AJ,
Well, everyone around here uses VB,
Why?

so it was a natural choice because
of the learning curve. I agree, this code is quite convoluted (it is
even more apparent now that I am looking at C# examples), maybe I'll
cut my losses and switchover to C#. It does look WAY easier!
Click to expand...

You are right, C# is easier, and 100 times more elegant and
professional. It's also standards based, so you have options to use it
on Linux too.
Anyway, strRegPath is just a parameter that I am passing from Main. Tis
just a path to the registry keys...
Click to expand...

OK, I only asked so I could test a much cleaner and meaner JScript
version which cuts out all the .NET bloat. You only need a few Kb of
DLLs to do this kind of thing, not 65Mb of badly designed bloatware.
BTW - I have figured it out and I changed my ManagementObject to a
ManagementBaseObject and now the keys are being removed...
Click to expand...

Great! Glad it's working now.
 
Hello Gerry,
Why?
Click to expand...

Not sure really, it seems to be the platform of choice for my company.
Probably because we are primarily a MS shop and the older developers
are used
to VB from version 2 on up...
You are right, C# is easier, and 100 times more elegant and
professional. It's also standards based, so you have options to use it
on Linux too.
Click to expand...

I have dabbled a little bit with C on unix a bit, and I like it and
understand it better
than the vb.net stuff... that does it, time to switch! On top of the
convoluted code
I have run into stumbling block after stumbling block trying to get
this application I
am writing to work in VB. I appears I can do the same thing in C# in
half the code.

Thank you for your input,

AJ Schroeder
 
Doh! I didn't even read that part in MSDN... <sigh>

I have coded quite a bit of this in WMI already, but there are just
some things that are
horribly complex in WMI, so I might just go ahead and try out
impersonation in VB and
then do the win32 registry classes.

WMI is cool, but just way too complex for what I am trying to do.

Thanks Ken,

Cheers,

AJ
 
AJ,
I am writing to work in VB. I appears I can do the same thing in C# in
half the code.
Click to expand...
This is mostly because somebody uses his basic programming language and
change only the keywords. Example

DataSet ds = new Dataset();
dim ds as New Dataset

which can as well written as
dim ds as Dataset = New DataSet

int i = Convert.ToInt32("1");
dim i as integer = CInt("1")
which can as well be written as
dim i as integer = Convert.ToInt32("1")

I hope this gives an idea what I want to tell

Cor
 
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