by Robert J May (1 Submission)
Category: OLE/COM/DCOM/Active-X
Compatability: Visual Basic 5.0
Difficulty: Intermediate
Date Added: Wed 3rd February 2021
Rating: 
(12 Votes)
This code shows how to register and unregister ActiveX dlls programatically, without relying on regsvr32 for the task. It's built into a reuseable class that can be put in your own code or compiled into a dll. Based very loosely on code from Vasudevan S.
Inputs
The file name
Code Returns
7 flags. See the enumeration and sample code for details.
API DeclarationsPrivate Declare Function LoadLibraryRegister Lib "KERNEL32" Alias "LoadLibraryA" (ByVal lpLibFileName As String) As Long
Private Declare Function FreeLibraryRegister Lib "KERNEL32" Alias "FreeLibrary" (ByVal hLibModule As Long) As Long
Private Declare Function CloseHandle Lib "KERNEL32" (ByVal hObject As Long) As Long
Private Declare Function GetProcAddressRegister Lib "KERNEL32" Alias "GetProcAddress" (ByVal hModule As Long, ByVal lpProcName As String) As Long
Private Declare Function CreateThreadForRegister Lib "KERNEL32" Alias "CreateThread" (lpThreadAttributes As Long, ByVal dwStackSize As Long, ByVal lpStartAddress As Long, ByVal lpparameter As Long, ByVal dwCreationFlags As Long, lpThreadID As Long) As Long
Private Declare Function WaitForSingleObject Lib "KERNEL32" (ByVal hHandle As Long, ByVal dwMilliseconds As Long) As Long
Private Declare Function GetExitCodeThread Lib "KERNEL32" (ByVal hThread As Long, lpExitCode As Long) As Long
Private Declare Sub ExitThread Lib "KERNEL32" (ByVal dwExitCode As Long)
VBcodersOption Explicit
Private Declare Function LoadLibraryRegister Lib "KERNEL32" Alias "LoadLibraryA" (ByVal lpLibFileName As String) As Long
Private Declare Function FreeLibraryRegister Lib "KERNEL32" Alias "FreeLibrary" (ByVal hLibModule As Long) As Long
Private Declare Function CloseHandle Lib "KERNEL32" (ByVal hObject As Long) As Long
Private Declare Function GetProcAddressRegister Lib "KERNEL32" Alias "GetProcAddress" (ByVal hModule As Long, ByVal lpProcName As String) As Long
Private Declare Function CreateThreadForRegister Lib "KERNEL32" Alias "CreateThread" (lpThreadAttributes As Long, ByVal dwStackSize As Long, ByVal lpStartAddress As Long, ByVal lpparameter As Long, ByVal dwCreationFlags As Long, lpThreadID As Long) As Long
Private Declare Function WaitForSingleObject Lib "KERNEL32" (ByVal hHandle As Long, ByVal dwMilliseconds As Long) As Long
Private Declare Function GetExitCodeThread Lib "KERNEL32" (ByVal hThread As Long, lpExitCode As Long) As Long
Private Declare Sub ExitThread Lib "KERNEL32" (ByVal dwExitCode As Long)
Private Const STATUS_WAIT_0 = &H0
Private Const WAIT_OBJECT_0 = ((STATUS_WAIT_0) + 0)
Private Const NOERRORS As Long = 0
Private Enum stRegisterStatus
stFileCouldNotBeLoadedIntoMemorySpace = 1
stNotAValidActiveXComponent = 2
stActiveXComponentRegistrationFailed = 3
stActiveXComponentRegistrationSuccessful = 4
stActiveXComponentUnRegisterSuccessful = 5
stActiveXComponentUnRegistrationFailed = 6
stNoFileProvided = 7
End Enum
Public Function Register(ByVal p_sFileName As String) As Variant
Dim lLib As Long
Dim lProcAddress As Long
Dim lThreadID As Long
Dim lSuccess As Long
Dim lExitCode As Long
Dim lThreadHandle As Long
Dim lRet As Long
On Error GoTo ErrorHandler
If lRet = NOERRORS Then
If p_sFileName = "" Then
lRet = stNoFileProvided
End If
End If
If lRet = NOERRORS Then
lLib = LoadLibraryRegister(p_sFileName)
If lLib = 0 Then
lRet = stFileCouldNotBeLoadedIntoMemorySpace
End If
End If
If lRet = NOERRORS Then
lProcAddress = GetProcAddressRegister(lLib, "DllRegisterServer")
If lProcAddress = 0 Then
lRet = stNotAValidActiveXComponent
Else
lThreadHandle = CreateThreadForRegister(0, 0, lProcAddress, 0, 0, lThreadID)
If lThreadHandle <> 0 Then
lSuccess = (WaitForSingleObject(lThreadHandle, 10000) = WAIT_OBJECT_0)
If lSuccess = 0 Then
Call GetExitCodeThread(lThreadHandle, lExitCode)
Call ExitThread(lExitCode)
lRet = stActiveXComponentRegistrationFailed
Else
lRet = stActiveXComponentRegistrationSuccessful
End If
End If
End If
End If
ExitRoutine:
Register = lRet
If lThreadHandle <> 0 Then
Call CloseHandle(lThreadHandle)
End If
If lLib <> 0 Then
Call FreeLibraryRegister(lLib)
End If
Exit Function
ErrorHandler:
lRet = Err.Number
GoTo ExitRoutine
End Function
Public Function UnRegister(ByVal p_sFileName As String) As Variant
Dim lLib As Long
Dim lProcAddress As Long
Dim lThreadID As Long
Dim lSuccess As Long
Dim lExitCode As Long
Dim lThreadHandle As Long
Dim lRet As Long
On Error GoTo ErrorHandler
If lRet = NOERRORS Then
If p_sFileName = "" Then
lRet = stNoFileProvided
End If
End If
If lRet = NOERRORS Then
lLib = LoadLibraryRegister(p_sFileName)
If lLib = 0 Then
lRet = stFileCouldNotBeLoadedIntoMemorySpace
End If
End If
If lRet = NOERRORS Then
lProcAddress = GetProcAddressRegister(lLib, "DllUnregisterServer")
If lProcAddress = 0 Then
lRet = stNotAValidActiveXComponent
Else
lThreadHandle = CreateThreadForRegister(0, 0, lProcAddress, 0, 0, lThreadID)
If lThreadHandle <> 0 Then
lSuccess = (WaitForSingleObject(lThreadHandle, 10000) = WAIT_OBJECT_0)
If lSuccess = 0 Then
Call GetExitCodeThread(lThreadHandle, lExitCode)
Call ExitThread(lExitCode)
lRet = stActiveXComponentUnRegistrationFailed
Else
lRet = stActiveXComponentUnRegisterSuccessful
End If
End If
End If
End If
ExitRoutine:
UnRegister = lRet
If lThreadHandle <> 0 Then
Call CloseHandle(lThreadHandle)
End If
If lLib <> 0 Then
Call FreeLibraryRegister(lLib)
End If
Exit Function
ErrorHandler:
lRet = Err.Number
GoTo ExitRoutine
End Function
