[RESOLVED] How to check registered ocx

[Fazar]

Haii
I want to check ocx that has already registered.
pls advice.

thanks.

[gavio]

Don't know, but, you can try unregistering and registering it:

Shell "regsvr32 ""C:\Path\To\Lib.ocx"" /u /s"
Shell "regsvr32 ""C:\Path\To\Lib.ocx"" /s"

Now it's registered for sure (if it exists of course). You can check if it exists before those Shell() calls:

If Dir$("C:\Path\To\Lib.ocx") <> vbNullString Then
  'do your thing...
End If

Anyway, i'm sure there's a better way to do it...

[mbshinde78]

Hi,

I found following code from from the web. Check if it works for you.

Option Explicit

Private Declare Function SetDllDirectoryA Lib "kernel32" ( _
    ByVal lpPathName As String) As Long
   
Private Declare Function LoadLibraryA Lib "kernel32" ( _
    ByVal lpLibFileName As String) As Long

Private Declare Function GetProcAddress Lib "kernel32" ( _
    ByVal hModule As Long, _
    ByVal lpProcName As String) As Long

Private Declare Function CallWindowProcA Lib "user32" ( _
    ByVal lpPrevWndFunc As Long, _
    ByVal hWnd As Long, _
    ByVal Msg As Long, _
    ByVal wParam As Long, _
    ByVal lParam As Long) As Long

Private Declare Function FreeLibrary Lib "kernel32" ( _
    ByVal hLibModule As Long) As Long

Private Const Reg       As String = "DllRegisterServer"
Private Const UnReg     As String = "DllUnregisterServer"

Public Enum Register_Params
    Register = 80000
    unRegister = 80001
End Enum

Public Function Invokes( _
    ByVal FileName As String, _
    ByVal PathName As String, _
    ByVal Action As Register_Params) As Boolean
   
    Dim hModule As Long
    Dim Address As Long
    '// Add extra path to default search paths for component
    If SetDllDirectoryA(PathName) Then
        '// Get a handle to the module
        hModule = LoadLibraryA(FileName)
        If hModule Then
        '// If the handle is valid, try to get the function address.
        Select Case Action
            Case Register
            Address = GetProcAddress(hModule, Reg)
            Case unRegister
            Address = GetProcAddress(hModule, UnReg)
        End Select
        '// If the address is valid call the function
            If Address Then
                CallWindowProcA Address, 0&, ByVal 0&, ByVal 0&, ByVal 0&
                FreeLibrary hModule
                Invokes = True
            End If
        End If
    End If

End Function

Private Sub Command1_Click()

    If Invokes("myolecmp.ocx", "c:\", Register) Then
        MsgBox "Success"
        Else
        MsgBox "Failed"
    End If

End Sub

Please comment and let others know if it works.

Cheers

[dilettante]

Do not use the self-registration entrypoints in this way.

Both of these methods risk trashing the component's registration. Proper registration is seldom done by running regsvr32 (which just calls these entrypoints like the code above is doing). It may be safe for older components like those VB6 creates and those dating to that era (1998) but the process is actually considerably more complex than that today.

A proper installer may set many other keys and values in the registry. This approach risks wiping those out.

See the Remarks at SelfReg Table for some of the cautions.

[Fazar]

it's work, but I just want checking that Ocx has already registered, not register or unregister the ocx. That is possible in vb?

thks.