FASM >> Assembly (x86) >> Win32 API >> Single Document Interface (SDI)

Handle Event

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參考資訊：
1. fasm

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

    format PE GUI 4.0
    entry start
  
    include "c:\fasm\include\win32a.inc"
 
    section ".idata" import data readable writeable
library user, "user32.dll", kernel, "kernel32.dll"
  
import user,                             \
    MessageBox,      "MessageBoxA",      \
    GetMessage,      "GetMessageA",      \
    DestroyWindow,   "DestroyWindow",    \
    RegisterClass,   "RegisterClassA",   \
    DefWindowProc,   "DefWindowProcA",   \
    CreateWindowEx,  "CreateWindowExA",  \
    DispatchMessage, "DispatchMessageA", \
    PostQuitMessage, "PostQuitMessage"
 
import kernel,                           \
    ExitProcess,     "ExitProcess",      \
    GetCommandLine,  "GetCommandLineA",  \
    GetModuleHandle, "GetModuleHandleA"
  
    section ".data" data readable writeable
szName      db       "main",0
CommandLine dd       0
hInstance   dd       0
wndClass    WNDCLASS <0>

    section ".text" code readable executable
proc WndProc hWnd, uMsg, wParam, lParam
    mov eax, [uMsg]
    cmp eax, WM_CLOSE
    je .handle_close
    cmp eax, WM_DESTROY
    je .handle_destroy
    invoke DefWindowProc, [hWnd], [uMsg], [wParam], [lParam]
    jmp .finish
 
.handle_close:
    invoke DestroyWindow, [hWnd]
    xor eax, eax
    jmp .finish
 
.handle_destroy:
    invoke PostQuitMessage, 0
    xor eax, eax
    jmp .finish
  
.finish:
    ret
endp

proc WinMain hInst, hPrevInst, CmdLine, CmdShow
    local msg:MSG

    mov [wndClass.lpfnWndProc], WndProc
    mov [wndClass.lpszClassName], szName
    invoke RegisterClass, wndClass
 
    invoke CreateWindowEx, WS_EX_LEFT, szName, szName, \
        WS_OVERLAPPEDWINDOW or WS_VISIBLE, 0, 0, 300, 300, NULL, NULL, NULL, NULL
 
@@:
    lea eax, [msg]
    invoke GetMessage, eax, NULL, 0, 0
    cmp eax, 0
    je @f
    lea eax, [msg]
    invoke DispatchMessage, eax
    jmp @b
@@:
    mov eax, [msg.wParam]
    ret
endp
 
start:
    invoke GetModuleHandle, NULL
    mov [hInstance], eax
  
    invoke GetCommandLine
    mov [CommandLine], eax
  
    stdcall WinMain, [hInstance], NULL, [CommandLine], SW_SHOWNORMAL
    invoke ExitProcess, eax

Line 32~36：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 37：其餘事件由系統代為處理

Makefile

export WINEPREFIX=/home/user/.wine_amd64

TARGET=main
MYWINE=box86 wine
FASM32=/home/user/.wine_amd64/drive_c/fasm

all:
	${MYWINE} ${FASM32}/fasm.exe ${TARGET}.asm

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

clean:
	rm -rf ${TARGET}.exe

編譯、執行

$ make
$ make run

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