Attached a demo showing how to all a DLL written in assembler (using the MasmBasic library).
When called from Excel, the user can choose to
- generate an exception
- see debug info in a console
- cancel
Here is the Excel code:
Private Declare Function RetHello Lib "\masm32\MasmBasic\Mb2VB\MbDllX.dll" _
(ByVal StrPtr As String, ByVal Ret$) As Long
Sub MbRetHello()
Dim rv As Long
Dim Ret As String
Ret = "This is the Ret$ - we use it to return text from the DLL to Excel" + Space$(100)
rv = RetHello("Click 'Yes' for a crash, 'No' for debug info:", Ret)
If rv = vbYes Then
MsgBox "You clicked yes - but you will never see this box!"
ElseIf rv = vbNo Then
MsgBox "You clicked NO"
ElseIf rv = vbCancel Then
MsgBox "You cancelled"
Else
MsgBox Ret, vbCritical, "You had a fat crash:"
End If
End Sub
This is the function exported by the DLL:
RetHello proc MyText, Ret$ ; $export Called from VBA as Declare Function ... As Long
VbDll ; serves to provide the SEH with the right return address
Try
invoke MessageBox, 0, MyText, Chr$("Do you want a nice exception"), MB_YESNOCANCEL or MB_ICONQUESTION
.if eax==IDYES
xor eax, eax ; set eax to zero
inc dword ptr [eax] ; that's pretty illegal...
.elseif eax==IDNO
pushad
invoke AllocConsole
fldpi ; set ST(0), just for fun
deb 4, "State of your application right now:", eax, ecx, edx, ebx, esi, edi, ebp, xmm0, xmm1, xmm2, ST(0), ST(1), ST(2), $Ret$:50, $MyText
Inkey "Hit any key to exit"
invoke FreeConsole
popad
.endif
Catch only
invoke MbCopy, Ret$, Cat$("Exception in DLL:"+CrLf$+"Address"+Tb$+Hex$(LastEx(addr))+CrLf$+"Code"+Tb$+Hex$(LastEx(code))), -1
Finally
ret
RetHello endp
Unzip the attachment with "use folder names" to your Masm32 drive, then launch Excel (tested with 2003, Excel 2010 doesn't like the SEH and crashes for 'Yes', but debugging works). In the VB editor window, import the *.bas file and run the macro. The library source (\Masm32\MasmBasic\MB2VB\MbDllX.asc) is set up for use with RichMasm.
Jochen,
thank you. Excellent work. :t
Gunther
:t Thanks
My current project is handling excell VBA. Why each time I had a project there always post about it, just coincidence?
Quote from: Farabi on January 16, 2013, 09:20:07 AM
Why each time I had a project there always post about it, just coincidence?
No, I can read your thoughts ::)
Jokes apart: What are you planning with VBA?
Quote from: jj2007 on January 16, 2013, 10:14:00 AM
Quote from: Farabi on January 16, 2013, 09:20:07 AM
Why each time I had a project there always post about it, just coincidence?
No, I can read your thoughts ::)
Jokes apart: What are you planning with VBA?
I had an order to create an academic system. A simple one.
Hi Jochen,
Quote from: jj2007 on January 16, 2013, 10:14:00 AM
No, I can read your thoughts ::)
that's very impressive. You're a mind spook. :lol: :lol:
Gunther