Excel coredumps with each call to a dll - for function RegQueryValueExA in advapi32.dll

Thread view:

Enable EMail Alerts

Start New Thread

Thread rating:

Tom Med - 18 Sep 2007 19:39 GMT

I am using a call to the following function

Private Declare Function RegQueryValueEx Lib "advapi32.dll" Alias _
"RegQueryValueExA" (ByVal hKey As Long, _
ByVal lpValueName As String, _
ByVal lpReserved As Long, _
lpType As Long, _
lpData As Any, _
lpcbData As Long) As Long

I then use this in code as follows, and each time I run it excel just
dies horribly. Is there something I am doing wrong? has anyone got
any working examples of RegQueryValueEx ?
I have checked the dll file exists and has this function call

Thanks
Tom

' Hello, World! for the Registry: gets this machine's name and prints
' it out.
Public Sub tempreg()

Dim pszName As String
Dim nNameLen As Long: nNameLen = 255
Dim hkResult As Long, hStartKey As Long
Dim nResult As Long
Dim nResult2
hStartKey = HKEY_LOCAL_MACHINE
nResult = ERROR_SUCCESS

nResult = RegOpenKeyEx(hStartKey, _
"SYSTEM\\CurrentControlSet\\Control\\ComputerName\
\ActiveComputerName", _
0&, KEY_READ, hkResult)
If (ERROR_SUCCESS = nResult) Then
nResult = RegQueryValueEx(hkResult, "ComputerName", 0, 0,
pszName, nNameLen)
If (ERROR_SUCCESS = nResult) Then
MsgBox "Hello, world, from " & pszName
Else
MsgBox "I don't even know my own name."
End If
End If
End Sub

Reply to this Message

Tom Med - 18 Sep 2007 19:49 GMT

> I am using a call to the following function
>
[quoted text clipped - 13 lines]
> Thanks
> Tom

Have now modified this to reserve memory in the result string, but it
still cores

Tom

Public Sub tempreg()

Dim pszName As String
Dim nNameLen As Long: nNameLen = 255
Dim hkResult As Long, hStartKey As Long
Dim nResult As Long
Dim nResult2

hStartKey = HKEY_LOCAL_MACHINE
pszName = Space$(nNameLen + 1)
nResult = ERROR_SUCCESS

nResult = RegOpenKeyEx(hStartKey, _
"SYSTEM\\CurrentControlSet\\Control\\ComputerName\
\ActiveComputerName", _
0&, KEY_READ, hkResult)
If (ERROR_SUCCESS = nResult) Then
nResult2 = RegQueryValueEx(hkResult, "ComputerName", 0, 0,
pszName, nNameLen)
If (ERROR_SUCCESS = nResult) Then
MsgBox "Hello, world, from " & pszName
Else
MsgBox "I don't even know my own name."
End If
End If
'RegCloseKey hkResult
End Sub

Reply to this Message

Tom Med - 18 Sep 2007 20:09 GMT

> > I am using a call to the following function
>
[quoted text clipped - 13 lines]
> > Thanks
> > Tom

Have finally got this working, it seems you have to pass in an array
of bytes as your buffer. You have to love VBA for being so un-user
friendly when it meets errors

' Hello, World! for the Registry: gets this machine's name and prints
' it out.
Public Sub tempreg()

Dim pszName As String
Dim ByteArray() As Byte
Dim ByteString As String
Dim KeyType As Long

Dim nNameLen As Long: nNameLen = 255
Dim hkResult As Long, hStartKey As Long
Dim nResult As Long

ReDim ByteArray(nNameLen)

hStartKey = HKEY_LOCAL_MACHINE
pszName = Space$(nNameLen + 1)
nResult = ERROR_SUCCESS

nResult = RegOpenKeyEx(hStartKey, _
"SYSTEM\\CurrentControlSet\\Control\\ComputerName\
\ActiveComputerName", _
REG_OPTION_NON_VOLATILE, KEY_READ, hkResult)
If (ERROR_SUCCESS = nResult) Then
nResult = RegQueryValueEx(hkResult, "ComputerName", 0&,
KeyType, ByteArray(0), nNameLen)
CopyMemory ByVal pszName, ByteArray(0), nNameLen
If (ERROR_SUCCESS = nResult) Then
MsgBox "Hello, world, from " & pszName
Else
MsgBox "I don't even know my own name."
End If
End If
'RegCloseKey hkResult
End Sub

Reply to this Message

Chip Pearson - 18 Sep 2007 21:58 GMT

You can use the GetComputerName API:

Public Declare Function GetComputerName Lib "kernel32" Alias
"GetComputerNameA" ( _
ByVal lpBuffer As String, _
nSize As Long) As Long

Sub AAA()
Dim CompName As String
Dim N As Long
Dim R As Long
N = 255
CompName = String$(N, vbNullChar)
R = GetComputerName(CompName, N)
If R Then
CompName = Left(CompName, N)
End If
Debug.Print CompName
End Sub

or even use Environ:

Sub BBB()
Debug.Print Environ("ComputerName")
End Sub

This is much simpler than jumping through the hoops of the registry.

Signature

Cordially,
Chip Pearson
Microsoft MVP - Excel
Pearson Software Consulting
www.cpearson.com
(email on the web site)

>> > I am using a call to the following function
>>
[quoted text clipped - 53 lines]
> 'RegCloseKey hkResult
> End Sub

Reply to this Message

Tom Med - 19 Sep 2007 15:37 GMT

Thanks, the variable from the registry was academic, I just took that
one from an example in c# that I knew worked. I thought if I gave the
example of the application specific value I actually needed it might
just confuse people in my post.

> You can use the GetComputerName API:
>
[quoted text clipped - 30 lines]
> Pearson Software Consultingwww.cpearson.com
> (email on the web site)

Reply to this Message