The MASM Forum Archive 2004 to 2012

I've writtten the following program:

***
include \masm32\include\masm32rt.inc


.data
  wnd_name BYTE "Windows App",0
  cls_name BYTE "Window0",0
  MainWin WNDCLASS <NULL, WinProc, NULL,NULL,NULL, NULL, NULL, COLOR_WINDOW, NULL, cls_name>
  msg     MSGStruct <>
  winRect RECT <>
  hMainWnd DWORD ?
  hInstance DWORD ?

.code
WinMain proc
      ; Get a handle to the current process
      INVOKE GetModuleHandle, NULL
      mov hInstance, eax
      mov MainWin.hInstance, eax

      ; Register the window class
      INVOKE RegisterClass, ADDR MainWin
     
      ; Create the application's main window
      INVOKE CreateWindowEx, 0, ADDR cls_name, ADDR wnd_name, NULL, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, NULL, NULL, hInstance, NULL

      ; Save the window handle, show the window
      mov hMainWnd, eax
      INVOKE ShowWindow, hMainWnd, SW_SHOW
      INVOKE UpdateWindow, hMainWnd

      ; Begin the program's message loop
      Message_Loop:
        INVOKE GetMessage, ADDR msg, NULL, NULL, NULL

        .IF eax == 0
          jmp Exit_Program
        .ENDIF
       
        INVOKE DispatchMessage, ADDR msg
        jmp Message_Loop
     
     Exit_Program:
       INVOKE ExitProcess, 0
WinMain endp


WinProc PROC,
  hWnd:DWORD, localMsg:DWORD, wParam:DWORD, lParam:DWORD
 
  mov eax, localMsg
  .IF eax == WM_LBUTTONDOWN
    ret
  .ENDIF
WinProc ENDP
end WinMain

***

When i attempt to assemble it I get the following errors:

***
Microsoft (R) Macro Assembler Version 6.14.8444
Copyright (C) Microsoft Corp 1981-1997.  All rights reserved.

Assembling: c:\asm\window0.asm
c:\asm\window0.asm(8) : error A2008: syntax error : msg
c:\asm\window0.asm(33) : error A2006: undefined symbol : msg
c:\asm\window0.asm(33) : error A2114: INVOKE argument type mismatch : argument :
1
c:\asm\window0.asm(39) : error A2006: undefined symbol : msg
c:\asm\window0.asm(39) : error A2114: INVOKE argument type mismatch : argument :
1
_
Assembly Error
***

It seems to be saying that something is wrong with the declaration of msg. But what could that be?

E.

It should be MSG instead of MSGStruct

Thanks! It assembles now! But when I try to run the program I get the message:

"window0.exe has encountered a problem and needs to close.  We are sorry for the inconvenience."

I can't see what I've done wrong...

E.

I guess there is problem with the initialization of your variables, have a look at Iczelion's tutorial #3 to see an example :

.
.
.
.data
ClassName db "SimpleWinClass",0
AppName  db "Our First Window",0

.data?
hInstance HINSTANCE ?
CommandLine LPSTR ?
.code
start:
invoke GetModuleHandle, NULL
mov    hInstance,eax
invoke GetCommandLine
mov    CommandLine,eax
invoke WinMain, hInstance,NULL,CommandLine, SW_SHOWDEFAULT
invoke ExitProcess,eax

WinMain proc hInst:HINSTANCE,hPrevInst:HINSTANCE,CmdLine:LPSTR,CmdShow:DWORD
LOCAL wc:WNDCLASSEX      ; <----- structures here defined
LOCAL msg:MSG            ; <-----
LOCAL hwnd:HWND
.
.
.