Writing DWORD values to the registry.

[Bomber]

Hi all,

I have this code

Option Explicit
Private Declare Function RegOpenKey Lib "advapi32.dll" Alias "RegOpenKeyA" (ByVal hkey As Long, ByVal lpSubKey As String, phkResult As Long) As Long
Private Declare Function RegCloseKey Lib "advapi32.dll" (ByVal hkey As Long) As Long
Private Declare Function RegSetValueEx Lib "advapi32.dll" Alias "RegSetValueExA" (ByVal hkey As Long, ByVal lpValueName As String, ByVal Reserved As Long, ByVal dwType As Long, ByVal lpData As String, ByVal cbData As Long) As Long
Private Const HKEY_LOCAL_MACHINE = &H80000002
Private Const REG_DWORD = 4
Dim nBufferKey As Long
Dim nVal As Long
 
Private Sub Form_Load()
    nVal = 2
    RegOpenKey HKEY_LOCAL_MACHINE, "SOFTWARE\Microsoft\Jet\4.0\Engines", nBufferKey
    RegSetValueEx nBufferKey, "SandBoxMode", 0, REG_DWORD, nVal, Len(nVal)
    'MsgBox "Sandbox Mode Changed", vbInformation, "Sandbox"
    RegCloseKey nBufferKey
    Unload Me
End Sub

All I am try to do is write a DWORD value of 2 to the registry. The above code does work without error but the key has a value of 32(50), if I change nVal to 0 the key reads 30(48). Can anyone assist in get the key to read 2.

[iburyak]

Hi all,

I have this code

Option Explicit
Private Declare Function RegOpenKey Lib "advapi32.dll" Alias "RegOpenKeyA" (ByVal hkey As Long, ByVal lpSubKey As String, phkResult As Long) As Long
Private Declare Function RegCloseKey Lib "advapi32.dll" (ByVal hkey As Long) As Long
Private Declare Function RegSetValueEx Lib "advapi32.dll" Alias "RegSetValueExA" (ByVal hkey As Long, ByVal lpValueName As String, ByVal Reserved As Long, ByVal dwType As Long, ByVal lpData As String, ByVal cbData As Long) As Long
Private Const HKEY_LOCAL_MACHINE = &H80000002
Private Const REG_DWORD = 4
Dim nBufferKey As Long
Dim nVal As Long
 
Private Sub Form_Load()
    nVal = 2
    RegOpenKey HKEY_LOCAL_MACHINE, "SOFTWARE\Microsoft\Jet\4.0\Engines", nBufferKey
    RegSetValueEx nBufferKey, "SandBoxMode", 0, REG_DWORD, nVal, Len(nVal)
    'MsgBox "Sandbox Mode Changed", vbInformation, "Sandbox"
    RegCloseKey nBufferKey
    Unload Me
End Sub

All I am try to do is write a DWORD value of 2 to the registry. The above code does work without error but the key has a value of 32(50), if I change nVal to 0 the key reads 30(48). Can anyone assist in get the key to read 2.

I didn't test your code but at a first glance

You are passing integer to a string requested value so convert to string before passing.

Dim nVal As Long
ByVal lpData As String

[PHP]Private Declare Function RegSetValueEx Lib "advapi32.d ll" Alias "RegSetValueExA " (ByVal hkey As Long, ByVal lpValueName As String, ByVal Reserved As Long, ByVal dwType As Long, ByVal lpData As String, ByVal cbData As Long) As Long[/PHP]

Also I would do this

[PHP]If RegOpenKey( HKEY_LOCAL_MACH INE, "SOFTWARE\Micro soft\Jet\4.0\En gines", nBufferKey) = ERROR_SUCCESS Then
RegSetValueEx nBufferKey, "SandBoxMod e", 0, REG_DWORD, nVal, Len(nVal)
End If[/PHP]

[Bomber]

I didn't test your code but at a first glance

You are passing integer to a string requested value so convert to string before passing.

Dim nVal As Long
ByVal lpData As String

[PHP]Private Declare Function RegSetValueEx Lib "advapi32.d ll" Alias "RegSetValueExA " (ByVal hkey As Long, ByVal lpValueName As String, ByVal Reserved As Long, ByVal dwType As Long, ByVal lpData As String, ByVal cbData As Long) As Long[/PHP]

Also I would do this

[PHP]If RegOpenKey( HKEY_LOCAL_MACH INE, "SOFTWARE\Micro soft\Jet\4.0\En gines", nBufferKey) = ERROR_SUCCESS Then
RegSetValueEx nBufferKey, "SandBoxMod e", 0, REG_DWORD, nVal, Len(nVal)
End If[/PHP]

If I dim nVal as a string, then the result is the DWORD value becomes invalid once the code is ran. So I'm not really sure I'm passing nVal as a string by declaring it as a string, is that enough?

I may also use the second code quote, thanks.

[Airton Barbosa]

That happends because DWORD way for "RegSetValu eEx" reads the "nVal" component of the pinvoke as an ASCII character. A string that receives "0" is "30" in ASCII hex, same for "1" -> "31" and "2" -> "32".

To set the DWORD registry "0x00000000 " just use the string representation of 0 ASCII member which is "\u0000".

Example:

string value = "\u0000"; //To set 0 for DWORD registry

RegSetValueEx nBufferKey, "SandBoxMod e", 0, REG_DWORD, value, Len(nVal)//Setting the string "value" for the pinvoke