Bagi pembuat aplikasi desktop pada windows, kita bisa memanfaatkan registry untuk settingan program aplikasi yang kita buat. Ini dianggap jauh lebih baik dari pada menggunakan ini file sebagai file sistemnya. Cuman ada beberapa yang perlu diperhatikan dalam menggunakan registry sebagai file settingan: Pertama, file registry hanya dapat diread and write oleh user setaraf admin, jadi jika kita membuat aplikasi maintenance untuk merubah settingan aplikasi di registry tidak akan jalan jika user login windows dengan level bukan admin. Kedua, perlu diperhatikan jangan sampai file registry menumpuk karena banyaknya aplikasi yang menyimpan settingan di registry. Untuk itu perlu dibuat juga program untuk membersihkan registry jika program di uninstall.

Berikut contoh aplikasi untuk mencatat, membaca, dan menghapus registry menggunakan VB6

Tambahkan listing code dibawah ini ke sebuah file module

Declare Function RegCreateKey Lib “advapi32.dll� Alias “RegCreateKeyA� _
(ByVal hKey As Long, ByVal lpSubKey As String, phkResult As Long) As Long
Declare Function RegCloseKey Lib “advapi32.dll� (ByVal hKey As Long) As Long
Declare Function RegOpenKeyEx Lib “advapi32.dll� Alias “RegOpenKeyExA� _
(ByVal hKey As Long, ByVal lpSubKey As String, ByVal ulOptions As Long, _
ByVal samDesired As Long, phkResult As Long) As Long
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
Declare Function RegOpenKey Lib “advapi32.dll� Alias “RegOpenKeyA� _
(ByVal hKey As Long, ByVal lpSubKey As String, phkResult As Long) As Long
Declare Function RegQueryValueEx Lib “advapi32.dll� Alias “RegQueryValueExA� _
(ByVal hKey As Long, ByVal lpValueName As String, ByVal lpReserved As Long, _
lpType As Long, ByVal lpData As String, lpcbData As Long) As Long
Declare Function RegDeleteKey Lib “advapi32.dll� Alias “RegDeleteKeyA� _
(ByVal hKey As Long, ByVal lpSubKey As String) As Long
Declare Function RegSetValueExString Lib “advapi32.dll� Alias “RegSetValueExA� _
(ByVal hKey As Long, ByVal lpValueName As String, ByVal Reserved As Long, _
ByVal dwType As Long, ByVal lpValue As String, ByVal cbData As Long) As Long

Const KEY_ENUMERATE_SUB_KEYS = &H8&
Const KEY_SET_VALUE = &H2&
Const READ_CONTROL = &H20000
Const KEY_CREATE_SUB_KEY = &H4&
Const KEY_QUERY_VALUE = &H1&
Const KEY_NOTIFY = &H10&
Const STANDARD_RIGHTS_WRITE = READ_CONTROL
Const STANDARD_RIGHTS_READ = READ_CONTROL
Const KEY_READ = STANDARD_RIGHTS_READ Or KEY_QUERY_VALUE Or _
KEY_ENUMERATE_SUB_KEYS Or KEY_NOTIFY

Const KEY_WRITE = STANDARD_RIGHTS_WRITE Or KEY_SET_VALUE Or KEY_CREATE_SUB_KEY
Const HKEY_CLASSES_ROOT = &H80000000
Const HKEY_CURRENT_USER = &H80000001
Const HKEY_LOCAL_MACHINE = &H80000002
Const HKEY_USERS = &H80000003
Const HKEY_PERFORMANCE_DATA = &H80000004
Const HKEY_CURRENT_CONFIG = &H80000005
Const HKEY_DYN_DATA = &H80000006
Const REG_SZ = 1&
Const ERROR_SUCCESS = 0&

Dim strHKey As String
Dim key As Long
Dim hKey As Long

Public Property Let SetHkey(vcHkey As String)
strHKey = vcHkey
End Property

Function CreateKey(SubKey As String)
If strHKey = “HKEY_CLASSES_ROOT� Then
key = RegCreateKey(HKEY_CLASSES_ROOT, SubKey, hKey)
ElseIf strHKey = “HKEY_CURRENT_USER� Then
key = RegCreateKey(HKEY_CURRENT_USER, SubKey, hKey)
ElseIf strHKey = “HKEY_LOCAL_MACHINE� Then
key = RegCreateKey(HKEY_LOCAL_MACHINE, SubKey, hKey)
ElseIf strHKey = “HKEY_USERS� Then
key = RegCreateKey(HKEY_USERS, SubKey, hKey)
ElseIf strHKey = “HKEY_CURRENT_CONFIG� Then
key = RegCreateKey(HKEY_CURRENT_CONFIG, SubKey, hKey)
End If

If key = ERROR_SUCCESS Then
key = RegCloseKey(hKey)
End If
End Function

‘gunakan function ini untuk membuat key dan mengisi value

Function SetStringValue(SubKey As String, Entry As String, Value As String)
If strHKey = “HKEY_CLASSES_ROOT� Then
key = RegOpenKeyEx(HKEY_CLASSES_ROOT, SubKey, 0, KEY_WRITE, hKey)
ElseIf strHKey = “HKEY_CURRENT_USER� Then
key = RegOpenKeyEx(HKEY_CURRENT_USER, SubKey, 0, KEY_WRITE, hKey)
ElseIf strHKey = “HKEY_LOCAL_MACHINE� Then
key = RegOpenKeyEx(HKEY_LOCAL_MACHINE, SubKey, 0, KEY_WRITE, hKey)
ElseIf strHKey = “HKEY_USERS� Then
key = RegOpenKeyEx(HKEY_USERS, SubKey, 0, KEY_WRITE, hKey)
ElseIf strHKey = “HKEY_CURRENT_CONFIG� Then
key = RegOpenKeyEx(HKEY_CURRENT_CONFIG, SubKey, 0, KEY_WRITE, hKey)
End If

If key = ERROR_SUCCESS Then
key = RegSetValueEx(hKey, Entry, 0, REG_SZ, ByVal Value, Len(Value))
If Not key = ERROR_SUCCESS Then
MsgBox “Register connection � & Entry & � failed�, vbExclamation, “Confirm�
Exit Function
End If
key = RegCloseKey(hKey)
Else
MsgBox “Key value is not exists�, vbExclamation, “Confirm�
Exit Function
End If
MsgBox “Register connection � & Entry & � successfull�, vbInformation, “Confirm�
End Function

‘gunakan function ini untuk membaca value dengan key yang tertentu

Public Function GetStringValue(ByVal SubKey As String, ByVal sKeyName As String)
Dim lBufferSize As Long
Dim sBuffer As String

lBufferSize = 0
sBuffer = “�

If strHKey = “HKEY_CLASSES_ROOT� Then
key = RegOpenKeyEx(HKEY_CLASSES_ROOT, SubKey, 0, KEY_READ, hKey)
ElseIf strHKey = “HKEY_CURRENT_USER� Then
key = RegOpenKeyEx(HKEY_CURRENT_USER, SubKey, 0, KEY_READ, hKey)
ElseIf strHKey = “HKEY_LOCAL_MACHINE� Then
key = RegOpenKeyEx(HKEY_LOCAL_MACHINE, SubKey, 0, KEY_READ, hKey)
ElseIf strHKey = “HKEY_USERS� Then
key = RegOpenKeyEx(HKEY_USERS, SubKey, 0, KEY_READ, hKey)
ElseIf strHKey = “HKEY_CURRENT_CONFIG� Then
key = RegOpenKeyEx(HKEY_CURRENT_CONFIG, SubKey, 0, KEY_READ, hKey)
End If

If key = ERROR_SUCCESS Then
sBuffer = Space(255)
lBufferSize = Len(sBuffer)
key = RegQueryValueEx(hKey, sKeyName, 0, REG_SZ, sBuffer, lBufferSize)
If key = ERROR_SUCCESS Then
key = RegCloseKey(hKey)
sBuffer = Trim(sBuffer)
GetStringValue = Left(sBuffer, lBufferSize - 1)
Else
GetStringValue = “�
MsgBox “Value � & sKeyName & � in � & strHKey & “\� & SubKey & _
� is empty�, vbExclamation, “Confirm�
End If
Else
GetStringValue = “�
MsgBox “Key � & strHKey & “\� & SubKey & � not exists�, vbExclamation, “Confirm�
End If
End Function

‘gunakan function ini untuk menghapus key beserta valuenya

Public Function DeleteKey(ByVal strKey As String) As Boolean
DeleteKey = False
If strHKey = “HKEY_CLASSES_ROOT� Then
key = RegDeleteKey(HKEY_CLASSES_ROOT, strKey)
ElseIf strHKey = “HKEY_CURRENT_USER� Then
key = RegDeleteKey(HKEY_CURRENT_USER, strKey)
ElseIf strHKey = “HKEY_LOCAL_MACHINE� Then
key = RegDeleteKey(HKEY_LOCAL_MACHINE, strKey)
ElseIf strHKey = “HKEY_USERS� Then
key = RegDeleteKey(HKEY_USERS, strKey)
ElseIf strHKey = “HKEY_CURRENT_CONFIG� Then
key = RegDeleteKey(HKEY_CURRENT_CONFIG, strKey)
End If

If key = ERROR_SUCCESS Then
MsgBox “Delete key in � & strHKey & “\� & strKey & � successfull�, _
vbInformation, “Confirm�
DeleteKey = True
Else
MsgBox “Delete key in � & strHKey & “\� & strKey & � failed�, _
vbExclamation, “Confirm�
End If
RegCloseKey (hKey)
End Function