I found this code on the web but it's witten in C. Can anyone translate this into VB please.
int _tmain(
int argc,
_TCHAR * argv[]
)
{
HRESULT hRes;
hRes = OleInitialize(NULL);
if (FAILED(hRes))
{
_tprintf("OleInitialize failed (0x%08X)\n", hRes);
return -1;
}
IRunningObjectTable * pROT = NULL;
IEnumMoniker * pEnum = NULL;
IMoniker * pMoniker = NULL;
IBindCtx * pBindCtx = NULL;
PWSTR pszName = NULL;
ULONG cElt;
for (;;)
{
// get interface pointer of the running object table
hRes = GetRunningObjectTable(NULL
if (FAILED(hRes))
{
_tprintf("GetRunningObject
break;
}
// create binding context object
hRes = CreateBindCtx(0, &pBindCtx);
if (FAILED(hRes))
{
_tprintf("CreateBindCtx failed (0x%08X)\n", hRes);
break;
}
// enumerate running objects
hRes = pROT->EnumRunning(&pEnum);
if (FAILED(hRes))
{
_tprintf("IRunningObjectTa
hRes);
break;
}
// go through all monikers in the table and display moniker name
while (pEnum->Next(1, &pMoniker, &cElt) == S_OK)
{
hRes = pMoniker->GetDisplayName(p
if (FAILED(hRes))
{
_tprintf("IMoniker::GetDis
break;
}
_tprintf("%ls\n", pszName);
CoTaskMemFree(pszName);
pMoniker->Release();
pszName = NULL;
pMoniker = NULL;
}
break;
}
if (pszName != NULL)
CoTaskMemFree(pszName);
if (pMoniker != NULL)
pMoniker->Release();
if (pEnum != NULL)
pEnum->Release();
if (pBindCtx != NULL)
pBindCtx->Release();
if (pROT != NULL)
pROT->Release();
OleUninitialize();
return 0;
}
I'll increase the points if I get a working VB example.
Thank you.
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Truth, I could do it, I've done such translations before and this is not that different, but it's a significant programming effort that I won't perform for the 125 points you're offering.
I offer the following link
http://msdn.microsoft.com/
so you can do the job yourself. It should be straightforward, but you will need to access the MSDN Library many times to get the sizes of the relevant structures. If you need assistance with specific pieces of your effort, please let me know.
It's not a third party dll...its a type library giving you access to certain API calls that are otherwise more complex to work with, or unattainable from VB. You also don't need to distribute this type library with your VB application...it is compiled into the program.
(this is w/ respect to EDDYKT's post)
cpkilekofp ,
I have increased the points to 500 so I hope someone can offer a solution.
What I am really after is : "How to enumerate the ROT and get a pointer to the Documents and applications registered in it "
So let's say there are three Excel Applications running at the same time. I want to get a pointer to each and every one of these 3 applications and their respective Workbooks by enumerating the ROT.This is so I can automate each all the 3 apps in my Client code.
Note that If I use the VB ' GetObject ' Function, I will only get a pointer to the first Excel app only !
The C code I initially posted was just so that I could show that it CAN BE DONE via API calls only ie: without having to use a third party dll.
Surely , this can't be that difficult !! isn't it ?
I hope I have explained this clearly. ...
AzraSound,
I really don't want to use any non built-in dlls.
The OLELIB.TLB lib is ,as you said, just a wrapper for what can be achieved from scrach via plain COM related APIs like EnumerateRot , GetRunningObjectTable , RegisterActiveObject.....e
For educational reasons and for portability reasons, I would love to see how this can be done in VB from scrach without having to resort to any dll wrappers.
Thanks.
I've never worked with those APIs, but some APIs simply arent accessible from VB b/c of the data types involved (e.g., certain callback function pointers), and a type library is our only outlet to gain access to them. It may be such is the case with the COM related API.
Also, it is no surprise you cannot find such code in VB. VB is a very high level language...most all VB developers are not concerned about lower level details. Most even avoid any API when possible. Microsoft knows this and that is why all the intrinsic behavior of COM was hidden from the VB developer. I mention this only to explain why an example such as what you are seeking is not being easily found in VB code.
Thanks AzraSound,
I recently bought myself an advanced VB6 book titled : "Advanced Visual Basic 6 " by 'Matthew Curland' which does deal with this ROT business and goes deeper into the hidden inner workings of VB. This proves that Yes, VB can indeed do this as well ! ...maybe it's more difficult but it CAN be done.
Unfortunately, the way this subject is explained in the book is so shallow and vague.... And to make things worse, the codes are annoyingly wrapped in overwhelmingly complex and lenghthy Classes. So really, I haven't benefited from the book at all and I am very disappointed.
I still haven't given up hope completely on this . I am sure someone knows how to do this.
References to COM objects and type libraries is not necessarily compiled into Visual Basic, either (look up the topic of Late Binding). OLELIB.TLB can be easily linked in to a VBA app associated with Excel (which still uses the word 'macro' to describe such) by opening the Visual Basic Editor, going to Tools/References, and (if it is registered) looking it up in the list, or (if it is unregistered) browsing for it (note the Browse button) which will register it on selection.
The problem is, normally you can't call the member functions of a C++ object (which is what most of the code is doing, something I should have observed but didn't the first time I replied). I've usually seen that written as "it's impossible" but I've done a few impossible things before (and busted my head against some REALLY impossible things). I've had time to think about attempting it in straight VB, and I believe it to be at least a midterm project, and possibly a senior research project, and highly likely to end in failure...and I'd simply wind up duplicating in a very ugly fashion the functionality that OLELIB.TLB seems to offer (and it does seem popular based on a quick Web search).
Why not try downloading it either from the author's page? The link given didn't work for me, but a Web search will give you multiple places to get it from. It definitely has the functionality you need. Remember, the reason C++ is still around is that there are some things it can do much easier than in VB; after all, Windows and its various components are written in C++, so they can often be directly accessed from that language.
For this piece of advice, I don't expect any points ;-)
A type library is simply a wrapper for a set of COM objects. Information from the type library IS compiled into your executable IF you choose early binding. If not, the type library (once registered) can be used just as if it was a DLL for the purpose of referencing COM objects. (Anyone please feel free to correct me if I've inadvertently misstated something here).
In terms of late vs. early binding, even if you have the type library referenced in your project, this is still late binding:
Dim obj As Object
Set obj = New SomeObject.SomeClass
So, if you implement that in code, the type library info is not compiled into the exe, or do type libraries not allow this type of late binding, or does this still work fine w/o requiring distribution of the type library?
cpkilekofp ,
I knew how to register OLELIB.TLB and set a reference to it in VBA via Tools\References...I fact, I dowloaded this lib in the past and worked just fine as expected.
However, as I said earlier , I wanted to see how this could be done in VB from scratch just by using the numerous "ole32" COM related APIs. I tend to learn better from seeing , testing and analysing code examples rather than reading through endless theorical concepts.
I still wander how and why the "ole32" library and all its related COM API functions are exposed and accessible to VB if they can't (or shouldn't) be used !!
forgive me if I come accross as being repetitive and stubborn but I have this gut feeling someone out there must have done this before ....... Am I going to be lucky :)
Regards.
Well, one,
I still wander how and why the "ole32" library and all its related COM API functions are exposed and accessible to VB if they can't (or shouldn't) be used !!
contains an erroneous assumption: The ole32 library is not exposed to and cannot be loaded as a reference in Visual Basic.
These functions ARE exposed in VB.NET because Microsoft chose to expose them in the Common Language Runtime.
Someone built OLELIB.TLB to expose these functions in Visual Basic and other COM applications.
That someone built OLELIB.TLB in Visual C++.
Let's take an example: one of the things you have to do is load an enumerator with an interface IEnumMoniker. In order to be able to use the DLL functions called when you invoke methods on the IEnumMoniker interface, you have to know exactly what object is being represented by that interface. And so on for every interface you are using. It can be done, but it will take forever, and I suspect you may violate your Microsoft license to do it.
If you are having trouble processing the Advanced Visual Basic 6 book, you wouldn't understand the code that implements it in any case, I suspect; I doubt I could explain the techniques better than the author of that book does, particularly since I don't know them yet.
Finally, I'm going to give you a quote older than the Christian Era, delivered by Euclid the geometer to Ptolemy, Pharoah of Egypt, when asked to explain his subject to his sovereign:
"Sire, there is no royal road to geometry."
In this case, there seems to be no easily generated Visual Basic source code that will emulate the C code you have described. If such does exist, those who know how to do it may very well be forbidden to do it by non-disclosure agreements concerning the OLE runtime code (as this is what you have to hack in order to meet your demands).
If this does not answer your query, good luck, as I am done here.
Hello Azra!
>>...most all VB developers are not concerned about lower level details. Most even avoid any API when possible. <<
Not me :)
IMHO, it even can be done with plain VB (using hidden IUnknown + ObjPtr/VarPtr + CopyMemory(RULEZ!)), but, unfortunatelly, VBA have no XxxPtr hack :(, so you and EDDYKT are right - *.tlb is the only way
>>*.tlb is the only way<<
I was wrong! VB can everything :)
Here is the code (tested with VB, but IMHO, it'll work in VBA - I added VarPtr declaration from msvbvm and remove all calls to StrPtr)
'======== bas module code===========
Option Explicit
Public Declare Sub OleInitialize Lib "ole32.dll" (pvReserved As Any)
Public Declare Sub OleUninitialize Lib "ole32.dll" ()
Private Declare Function CallWindowProc Lib "user32" Alias "CallWindowProcA" (ByVal lpPrevWndFunc As Long, ByVal hwnd As Long, ByVal Msg As Long, ByVal wParam As Long, ByVal lParam As Long) As Long
Private Declare Sub CopyMemory Lib "kernel32" Alias "RtlMoveMemory" (lpDest As Any, lpSource As Any, ByVal cBytes As Long)
Private Declare Function PutMem2 Lib "msvbvm60" (ByVal pWORDDst As Long, ByVal NewValue As Long) As Long
Private Declare Function PutMem4 Lib "msvbvm60" (ByVal pDWORDDst As Long, ByVal NewValue As Long) As Long
Private Declare Function GetMem4 Lib "msvbvm60" (ByVal pDWORDSrc As Long, ByVal pDWORDDst As Long) As Long
Public Declare Function VarPtr Lib "msvbvm60" (var As Any) As Long
Private Declare Function GlobalAlloc Lib "kernel32" (ByVal wFlags As Long, ByVal dwBytes As Long) As Long
Private Declare Function GlobalFree Lib "kernel32" (ByVal hMem As Long) As Long
Private Declare Function CopyStringA Lib "kernel32" Alias "lstrcpyA" (ByVal NewString As String, ByVal OldString As Long) As Long
Private Declare Function lstrlenW Lib "kernel32" (ByVal lpString As Long) As Long
Private Declare Function lstrlenA Lib "kernel32" (ByVal lpString As Long) As Long
Private Declare Function WideCharToMultiByte Lib "kernel32" _
(ByVal codepage As Long, ByVal dwFlags As Long, _
lpWideCharStr As Any, ByVal cchWideChar As Long, _
lpMultiByteStr As Any, ByVal cchMultiByte As Long, _
ByVal lpDefaultChar As String, _
ByVal lpUsedDefaultChar As Long) As Long
Private Const GMEM_FIXED As Long = &H0
Private Const asmPUSH_imm32 As Byte = &H68
Private Const asmRET_imm16 As Byte = &HC2
Private Const asmRET_16 As Long = &H10C2&
Private Const asmCALL_rel32 As Byte = &HE8
'IUnknown vTable ordinals
Public Const unk_QueryInterface As Long = 0
Public Const unk_AddRef As Long = 1
Public Const unk_Release As Long = 2
'Function to call Interface members by ordinal in VTable
Public Function CallInterface(ByVal pInterface As Long, ByVal FuncOrdinal As Long, ByVal ParamsCount As Long, Optional ByVal p1 As Long = 0, Optional ByVal p2 As Long = 0, Optional ByVal p3 As Long = 0, Optional ByVal p4 As Long = 0, Optional ByVal p5 As Long = 0, Optional ByVal p6 As Long = 0, Optional ByVal p7 As Long = 0, Optional ByVal p8 As Long = 0, Optional ByVal p9 As Long = 0, Optional ByVal p10 As Long = 0) As Long
Dim i As Long, t As Long
Dim hGlobal As Long, hGlobalOffset As Long
If ParamsCount < 0 Then Err.Raise 5 'invalid call
If pInterface = 0 Then Err.Raise 5
'5 bytes for each parameter
'5 bytes - PUSH this
'5 bytes - call member function
'3 bytes - ret 0x0010, pop CallWindowProc
'1 byte - dword align.
hGlobal = GlobalAlloc(GMEM_FIXED, 5 * ParamsCount + 5 + 5 + 3 + 1)
If hGlobal = 0 Then Err.Raise 7 'insuff. memory
hGlobalOffset = hGlobal
If ParamsCount > 0 Then
t = VarPtr(p1)
For i = ParamsCount - 1 To 0 Step -1
PutMem2 hGlobalOffset, asmPUSH_imm32
hGlobalOffset = hGlobalOffset + 1
GetMem4 t + i * 4, hGlobalOffset
hGlobalOffset = hGlobalOffset + 4
Next
End If
'First member of any interface - this. Assign...
PutMem2 hGlobalOffset, asmPUSH_imm32
hGlobalOffset = hGlobalOffset + 1
PutMem4 hGlobalOffset, pInterface
hGlobalOffset = hGlobalOffset + 4
'Call IFace Function by its ordinal
PutMem2 hGlobalOffset, asmCALL_rel32
hGlobalOffset = hGlobalOffset + 1
GetMem4 pInterface, VarPtr(t) 'dereference: find vTable
GetMem4 t + FuncOrdinal * 4, VarPtr(t) 'Function offset in vTable, dereference
PutMem4 hGlobalOffset, t - hGlobalOffset - 4
hGlobalOffset = hGlobalOffset + 4
'all interfaces are stdcall, so forget about stack clearing
PutMem4 hGlobalOffset, asmRET_16 'ret 0x0010
CallInterface = CallWindowProc(hGlobal, 0, 0, 0, 0)
GlobalFree hGlobal
End Function
Public Function StrFromPtrA(ByVal lpszA As Long, Optional nSize As Long = 0) As String
Dim s As String, bTrim As Boolean
If nSize = 0 Then
nSize = lstrlenA(lpszA)
bTrim = True
End If
s = String(nSize, Chr$(0))
CopyStringA s, ByVal lpszA
If bTrim Then s = TrimNULL(s)
StrFromPtrA = s
End Function
Public Function StrFromPtrW(ByVal lpszW As Long, Optional nSize As Long = 0) As String
Dim s As String, bTrim As Boolean
If nSize = 0 Then
nSize = lstrlenW(lpszW) * 2
bTrim = True
End If
s = String(nSize, Chr$(0))
' CopyMemory ByVal StrPtr(s), ByVal lpszW, nSize ' VBA doesn't support StrPtr :(
WideCharToMultiByte 0, &H0, ByVal lpszW, -1, ByVal s, Len(s), &H0, &H0
If bTrim Then s = TrimNULL(s)
StrFromPtrW = s
End Function
Public Function TrimNULL(ByVal str As String) As String
If InStr(str, Chr$(0)) > 0& Then
TrimNULL = Left$(str, InStr(str, Chr$(0)) - 1&)
Else
TrimNULL = str
End If
End Function
'============Form code===========
Private Declare Function GetRunningObjectTable Lib "ole32.dll" (ByVal dwReserved As Long, pROT As Long) As Long
Private Declare Function CreateBindCtx Lib "ole32.dll" (ByVal dwReserved As Long, pBindCtx As Long) As Long
Private Declare Sub CoTaskMemFree Lib "ole32.dll" (ByVal pv As Long)
'Interface members ordinals
Private Const vtbl_ROT_EnumRunning = 9
Private Const vtbl_EnumMoniker_Next = 3
Private Const vtbl_Moniker_GetDisplayNam
Private Sub Command1_Click()
EnumRot
End Sub
Private Sub EnumRot()
Dim pROT As Long, pEnumMoniker As Long, pMoniker As Long, pBindCtx As Long
Dim ret As Long, nCount As Long
Dim pName As Long
ret = GetRunningObjectTable(0, pROT)
ret = CreateBindCtx(0, pBindCtx)
CallInterface pROT, vtbl_ROT_EnumRunning, 1, VarPtr(pEnumMoniker)
While CallInterface(pEnumMoniker
CallInterface pMoniker, vtbl_Moniker_GetDisplayNam
'For win9x you'll need StrFromPtrA
Debug.Print StrFromPtrW(pName)
CallInterface pMoniker, unk_Release, 0
CoTaskMemFree pName
Wend
CallInterface pEnumMoniker, unk_Release, 0
CallInterface pBindCtx, unk_Release, 0
CallInterface pROT, unk_Release, 0
End Sub
Regards
Ark
LOL Very cool stuff...I've tested this code in Excel 2002 and it works just fine (though you'll have to do some filtration, on my system a GUID showed up as the last entry, also showed objects for event handlers in macros).
Thank you very much, Ark. The techiniques here are going to help me eliminate a Visual C++ object from my distribution and replace its functionality with pure VB code. And congratulations (in advance) on 500 points very well earned.
Business Accounts
Answer for Membership
by: EDDYKTPosted on 2006-10-04 at 04:24:03ID: 17658418
check with this, never try by myself
http://www.experts-exchang
and download the OLELIB.TLB from
http://www.mvps.org/emorci