The MASM Forum Archive 2004 to 2012

What will be the best way to hook up to the computer keyboard so that it plays a typewriter sound every time a key is pressed.

I basically want to make a personal toy :)

this should give you a idea how it could be done  :bg:
include masm32rt.inc
WndProc     proto :DWORD,:DWORD,:DWORD,:DWORD
.data
.data?
    keys1       db 256 dup (?)
    keys2       db 256 dup (?)
   
    hInstance   dd ?
    wcex        WNDCLASSEX <>
    msg         MSG <>
.code

start:
    xor edi,edi
    .while edi < 256
        invoke GetAsyncKeyState,edi
        mov keys1[edi],ah
        inc edi
    .endw

    mov hInstance,rv(GetModuleHandle,0)
    mov wcex.hInstance,eax
    mov wcex.cbSize,SIZEOF WNDCLASSEX
    mov wcex.style, CS_HREDRAW or CS_VREDRAW
    mov wcex.lpfnWndProc, OFFSET WndProc
    mov wcex.cbClsExtra,NULL
    mov wcex.cbWndExtra,NULL
    mov wcex.hbrBackground,rv(CreateSolidBrush,0ffffffh)
    mov wcex.lpszMenuName,NULL
    mov wcex.lpszClassName,chr$("SomeClass32")
    mov wcex.hIcon,rv(LoadIcon,NULL,IDI_APPLICATION)
    mov wcex.hIconSm,eax
    mov wcex.hCursor,rv(LoadCursor,NULL,IDC_ARROW)
    invoke RegisterClassEx, OFFSET wcex
    fn CreateWindowEx,NULL\
                     ,wcex.lpszClassName\
                     ,"keys"\
                     ,WS_OVERLAPPEDWINDOW\
                     ,CW_USEDEFAULT,CW_USEDEFAULT,CW_USEDEFAULT,CW_USEDEFAULT\
                     ,NULL\
                     ,NULL\
                     ,hInstance\
                     ,NULL
    mov   edi,eax

    invoke ShowWindow,edi,SW_SHOWNORMAL
    invoke UpdateWindow,edi

    .while 1
        .break .if !rv(GetMessage,OFFSET msg,0,0,0)
        invoke TranslateMessage, OFFSET msg
        invoke DispatchMessage, OFFSET msg
    .endw
    invoke ExitProcess,msg.wParam


WndProc proc hWnd:HWND, uMsg:UINT, wParam:WPARAM, lParam:LPARAM
    .if uMsg == WM_DESTROY
        invoke PostQuitMessage,NULL
    .elseif uMsg == WM_CREATE
        invoke SetTimer,hWnd,0,1000/30,0    ; 30 times per second
    .elseif uMsg == WM_TIMER
        push ebx
        xor ebx,ebx
        .while ebx < 256                    ; get all key states
            invoke GetAsyncKeyState,ebx
            mov keys2[ebx],ah
            inc ebx
        .endw
        xor ebx,ebx
        .while ebx < 256
            movzx eax,keys1[ebx]
            movzx ecx,keys2[ebx]
            mov keys1[ebx],cl
            and eax,80h
            and ecx,80h
            .if !eax && ecx && ebx >= VK_A && ebx <=VK_Z
                invoke MessageBeep,MB_OK
            .endif
            inc ebx
        .endw
        pop ebx
    .else
        invoke DefWindowProc,hWnd,uMsg,wParam,lParam
        ret
    .endif

    xor eax,eax
    ret
WndProc endp
end start

I would set a global keyboard hook with SetWindowsHookEx and then every time a key is pressed your callback function is called.

That timer + GetAsyncKeyState looks like a very bad idea to me.

Quote from: BlackVortex on May 12, 2010, 12:41:46 AMThat timer + GetAsyncKeyState looks like a very bad idea to me.

well, it doesn't required a dll injection (which is done by SetWindowsHookEx)

So ? There is no performance loss, it's actually much much better. That's exactly what that function is for.

While they consider the complexities of the first half of the question I'll answer the second half :lol

invoke PlaySound, chr$("C:\masm32\typewriter.wav"), NULL, SND_FILENAME or SND_ASYNC