WIN32汇编－第一个窗口程序

.386
.model flat,stdcall
option casemap:none

include windows.inc
include  user32.inc
include kernel32.inc
includelib user32.lib
includelib kernel32.lib

.const
szClassName db 'MyWindow',0
szWinName db '第一个汇编窗口',0
szHello  db 'Hello',0

.data?
hInstance dd ?
hWinMain dd ?

.code

_WindowProc proc uses ebx esi edi,hwnd,uMsg,wParam,lParam
LOCAL @stPaint:PAINTSTRUCT
LOCAL @stRect:RECT
LOCAL @hdc
;mov eax,uMsg
.if uMsg == WM_CLOSE
  invoke DestroyWindow,hWinMain
  invoke PostQuitMessage,NULL
.elseif uMsg == WM_PAINT
  invoke BeginPaint,hWinMain,addr @stPaint
  mov @hdc,eax
  invoke GetClientRect,hWinMain,addr @stRect
  invoke DrawText,@hdc,offset szHello,-1,addr @stRect,DT_SINGLELINE or DT_CENTER or DT_VCENTER
  invoke EndPaint,hWinMain,addr @stPaint
.else
  invoke DefWindowProc,hwnd,uMsg,wParam,lParam
  ;ret ;这里注释掉后功能正常
.endif
;xor eax,eax  ;这里注释掉后功能正常
ret

_WindowProc endp

_Main proc
LOCAL @stWndClass:WNDCLASSEX
LOCAL @stMsg:MSG
invoke GetModuleHandle,NULL
mov hInstance,eax
invoke  RtlZeroMemory,addr @stWndClass,sizeof @stWndClass
invoke LoadCursor,NULL,IDC_ARROW
push hInstance
pop @stWndClass.hInstance
mov  @stWndClass.cbSize,sizeof @stWndClass
mov  @stWndClass.style,CS_VREDRAW or CS_HREDRAW
mov @stWndClass.lpfnWndProc,offset _WindowProc
mov @stWndClass.hbrBackground,COLOR_WINDOW + 1
mov @stWndClass.lpszClassName,offset szClassName
invoke  RegisterClassEx,addr @stWndClass
invoke CreateWindowEx,WS_EX_CLIENTEDGE,\
  offset szClassName,
  offset szWinName,
  WS_OVERLAPPEDWINDOW,
  CW_USEDEFAULT,
  CW_USEDEFAULT,
  CW_USEDEFAULT,
  CW_USEDEFAULT,
  NULL,NULL,hInstance,NULL
mov hWinMain,eax
invoke ShowWindow,hWinMain,SW_SHOWNORMAL
invoke UpdateWindow,hWinMain

.while TRUE
  invoke GetMessage,addr @stMsg,NULL,0,0
  .break .if eax == 0  
  invoke TranslateMessage,addr @stMsg
  invoke DispatchMessage,addr @stMsg
.endw
ret

_Main endp

start:
invoke _Main
invoke ExitProcess,NULL
end start

==========================================================================

以上程序摘自罗云彬的《Windows环境下32位汇编语言程序设计－琢石成器》

源代码通过Radasm编译运行通过