ASM Community

I am trying to figure out how to make a dll...
i have this code:



.386
.MODEL Flat, STDCALL

option casemap:none
include \masm32\include\windows.inc
include \masm32\include\kernel32.inc
includelib \masm32\lib\kernel32.lib
include \masm32\include\user32.inc
includelib \masm32\lib\user32.lib

.DATA
MsgBoxCaption db "What?",0
MsgBoxText db "Im in TESTDLL",0
MsgBoxTextB db "I'm in DllEntryPoint",0
.DATA?
.CONST
.CODE

TESTDLL PROC PUBLIC uses eax,vara:DWORD,varb:DWORD,varc:DWORD

;What this function should do is take vara and replace
;its value with varb...so vara will be the same as varb
mov varc, eax ;saves eax
mov eax, varb
mov vara, eax
invoke MessageBox, NULL, addr MsgBoxText, addr MsgBoxCaption, MB_OK ;shows we got into TESTDLL
invoke MessageBox, NULL, addr varb,addr vara,MB_OK ;how can i do this?
mov eax, varc ;puts original eax value back
ret

TESTDLL ENDP

DllEntryPoint proc hinstDll:dword,aReason:dword,aReserved:dword
mov eax,1
invoke MessageBox, NULL, addr MsgBoxTextB, addr MsgBoxCaption, MB_OK
ret
DllEntryPoint endp
end DllEntryPoint







i am calling TESTDLL from Visual Basic with this declaration:
Private Declare Function TESTDLL Lib "C:\asmdll1.dll" ( _
ByRef lngValue1 As Long, _
ByRef lngValue2 As Long, _
ByRef lngValue3 As Long)


this is the thing that calls TESTDLL:

Private Sub Command1_Click()

Dim a As Long
Dim b As Long
Dim c As Long


a = 32768
b = 65535
c = 12345

TESTDLL a, b, c
Debug.Print "a=" & CStr(a) & " b=" & CStr(b) & " c=" & CStr(c) & " d=" & CStr(d)

End Sub


after i run this, a should be the same as b...but they dont change!

also...is there a way to use MessageBox and put a DWORD in it? like this:

invoke MessageBox, NULL, addr varb,addr vara,MB_OK
varb is a DWORD passed from VB



hmmm....can anyone help me with this? :confused:
Thanks in Advance,
rkinasz :grin:

Dw2a.asm the invoke wsprintf you find it in the M32.lib if this is what you mean....

MessageBox needs an offset (pointer) of string. All you need is convert your dword to string, how - it is depend on what exactly you need decimal or hex or whatever.

And you don't need to save eax in your proc, uses eax already do that for you in the stack. Actually you don't need to save eax at all here.

see cmax suggestion above

are you talking about masm32.lib? i dont have a m32.lib...

in that one... i see dw2a, dwtoa, and dw2hex....but that is all