MASM
TITLE Windows Application (WinApp.asm)
.386
.MODEL flat,stdcall
INCLUDE SmallWin.inc ; kernel32.lib
INCLUDE GraphWin.inc ; user32.lib
.STACK 4096
;==================== DATA =======================
.data
PopupTitle BYTE "Popup Window",0
PopupText BYTE "This window was activated by a "
BYTE "WM_LBUTTONDOWN message",0
ErrorTitle BYTE "Error",0
WindowName BYTE "ASM Windows App",0
className BYTE "ASMWin",0
; Define the Application's Window class structure.
MainWin WNDCLASS <NULL,WinProc,NULL,NULL,NULL,NULL,NULL, \
COLOR_WINDOW,NULL,className>
msg MSGStruct <>
winRect RECT <>
hMainWnd DWORD ?
hInstance DWORD ?
;=================== CODE =========================
.code
WinMain PROC
; Get a handle to the current process.
INVOKE GetModuleHandle, NULL
mov hInstance, eax
mov MainWin.hInstance, eax
; Load the program's icon and cursor.
INVOKE LoadIcon, NULL, IDI_APPLICATION
mov MainWin.hIcon, eax
INVOKE LoadCursor, NULL, IDC_ARROW
mov MainWin.hCursor, eax
; Register the window class.
INVOKE RegisterClass, ADDR MainWin
.IF eax == 0
call ErrorHandler
jmp Exit_Program
.ENDIF
; Create the application's main window.
; Returns a handle to the main window in EAX.
INVOKE CreateWindowEx, 0, ADDR className,
ADDR WindowName,MAIN_WINDOW_STYLE,
CW_USEDEFAULT,CW_USEDEFAULT,CW_USEDEFAULT,
CW_USEDEFAULT,NULL,NULL,hInstance,NULL
mov hMainWnd,eax
; If CreateWindowEx failed, display a message & exit.
.IF eax == 0
call ErrorHandler
jmp Exit_Program
.ENDIF
; Show and draw the window.
INVOKE ShowWindow, hMainWnd, SW_SHOW
INVOKE UpdateWindow, hMainWnd
; Begin the program's message-handling loop.
Message_Loop:
; Get next message from the queue.
INVOKE GetMessage, ADDR msg, NULL,NULL,NULL
; Quit if no more messages.
.IF eax == 0
jmp Exit_Program
.ENDIF
; Relay the message to the program's WinProc.
INVOKE DispatchMessage, ADDR msg
jmp Message_Loop
Exit_Program:
INVOKE ExitProcess,0
WinMain ENDP
;-----------------------------------------------------
WinProc PROC,
hWnd:DWORD, localMsg:DWORD, wParam:DWORD, lParam:DWORD
; The application's message handler, which handles
; application-specific messages. All other messages
; are forwarded to the default Windows message
; handler.
;-----------------------------------------------------
mov eax, localMsg
.IF eax == WM_LBUTTONDOWN ; mouse button?
jmp WinProcExit
.ELSEIF eax == WM_CREATE ; create window?
..
jmp WinProcExit
.ELSEIF eax == WM_CLOSE ; close window?
..
INVOKE PostQuitMessage,0
jmp WinProcExit
.ELSE ; other message?
INVOKE DefWindowProc, hWnd, localMsg, wParam, lParam
jmp WinProcExit
.ENDIF
WinProcExit:
ret
WinProc ENDP
;---------------------------------------------------
ErrorHandler PROC
; Display the appropriate system error message.
;---------------------------------------------------
.data
pErrorMsg DWORD ? ; ptr to error message
messageID DWORD ?
.code
INVOKE GetLastError ; Returns message ID in EAX
mov messageID,eax
; Get the corresponding message string.
INVOKE FormatMessage, FORMAT_MESSAGE_ALLOCATE_BUFFER + \
FORMAT_MESSAGE_FROM_SYSTEM,NULL,messageID,NULL,
ADDR pErrorMsg,NULL,NULL
; Display the error message.
INVOKE MessageBox,NULL, pErrorMsg, ADDR ErrorTitle,
MB_ICONERROR+MB_OK
; Free the error message string.
INVOKE LocalFree, pErrorMsg
ret
ErrorHandler ENDP
END WinMain
SmallWin.inc