Netwide Assembler (NASM) >> Assembly (x86) >> Win32 API (NASMX) >> Single Document Interface (SDI)

Handle Event

---

參考資訊：
1. nasm
2. masm32

當視窗有事件需要被處理時，系統會透過呼叫註冊的Callback副程式來處理，而這個Callback副程式就是在註冊Class時，設定給lpfnWndProc的事件處理副程式，因此，當這個事件處理副程式被呼叫時，可以處理自己感興趣的事件，而其餘事件則交給系統處理(透過呼叫DefWindowProc())，需要注意的是，例如：WM_CLOSE，就必須由該視窗自己處理，因為系統無法知道還有哪些額外的資源需要被釋放掉

main.asm

    %include "c:\\nasmx\\inc\\nasmx.inc"
    %include "c:\\nasmx\\inc\\win32\\windows.inc"
    %include "c:\\nasmx\\inc\\win32\\user32.inc"
    %include "c:\\nasmx\\inc\\win32\\kernel32.inc"
 
    entry start
 
    section .data
szName       declare(NASMX_TCHAR) NASMX_TEXT("main"),0
CommandLine  dd 0
hInstance    dd 0
 
NASMX_ISTRUC msg, MSG
NASMX_IENDSTRUC

NASMX_ISTRUC wndClass, WNDCLASS
NASMX_IENDSTRUC
 
    section .text
proc WndProc, dword hWnd, uint_t uMsg, dword wParam, dword lParam
    locals none
 
    switch dword [argv(.uMsg)]
    case dword WM_CLOSE
        invoke DestroyWindow, [argv(.hWnd)]
        break
    case dword WM_DESTROY
        invoke PostQuitMessage, 0
        break
    default
        invoke DefWindowProc, [argv(.hWnd)], [argv(.uMsg)], [argv(.wParam)], [argv(.lParam)]
    endswitch
endproc

proc WinMain, dword hInst, dword hPrevInst, dword CmdLine, dword CmdShow
    locals none

    mov dword [wndClass + WNDCLASS.lpfnWndProc], WndProc
    mov dword [wndClass + WNDCLASS.lpszClassName], szName
    invoke RegisterClass, wndClass
    invoke CreateWindowEx, WS_EX_LEFT, szName, szName, \
        WS_OVERLAPPEDWINDOW | WS_VISIBLE, 0, 0, 300, 300, NULL, NULL, NULL, NULL
 
    do 
        invoke DispatchMessage, msg
        invoke GetMessage, msg, NULL, NULL, NULL
    while eax, !=, 0
 
    mov eax, dword [msg + MSG.wParam]
endproc
 
proc start, dword argc, dword argv
    locals none
 
    invoke GetModuleHandle, NULL
    mov [hInstance], eax
 
    invoke GetCommandLine, NULL
    mov [CommandLine], eax
 
    invoke WinMain, [hInstance], NULL, [CommandLine], SW_SHOWNORMAL
    invoke ExitProcess, NULL
endproc

Line 23~29：關閉視窗的順序為：主視窗收到WM_CLOSE事件時，呼叫DestroyWindow()，DestroyWindow()會自動將子視窗的相關資源也一併釋放掉(包含Resource描述的資源)，系統接著會發送WM_DESTROY事件給主視窗，待主視窗收到WM_DESTROY事件時，呼叫PostQuitMessage()結束視窗，值得注意的地方是，SendMessage()是屬於Block方式呼叫(必須等待動作執行完畢才返回)，而PostQuitMessage()則是Non-block方式呼叫
Line 30~31：其餘事件由系統代為處理

Makefile

export WINEPREFIX=/home/user/.wine_amd64

TARGET=main
MYWINE=box86 wine
NASM32=/home/user/.wine_amd64/drive_c/nasmx

all:
	${MYWINE} ${NASM32}/bin/nasm.exe -fwin32 ${TARGET}.asm
	${MYWINE} ${NASM32}/bin/GoLink.exe /entry _main ${TARGET}.obj kernel32.dll user32.dll

run:
	${MYWINE} ${TARGET}.exe

clean:
	rm -rf ${TARGET}.exe ${TARGET}.obj

編譯、執行

$ make
$ make run

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