在控制台 mfc 程序中检测转义键

Question

I am writing a small program in Visual Studio 11 (beta) that a console mfc app. I have never programmed for this environment before and I am trying to figure out how to detect the Escape-key press in the console. I have looked extensively at online resources and tried many different things can't figure it out.

Here is what I was trying to see if I could get it to work.

printf("Press Escape to exit.");
bool maxReached = true;
while (maxReached)
{
    if(WM_COMMAND == IDCANCEL) // Tried many different things here, like WM_KEYDOWN == VK_ESCAPE. no luck
    {
        maxReached = false;
    }
}
exit(-1);

Any help would be much appreciated.

Kamal

Answer 1

You can detect using

if (getch() == 0x1B) // escape detected
{
  maxReached = false;
}

Answer 2

You can always install a keyboard hook and check for the ESC key being pressed.
Here's how:

First, install the hook

HHOOK hhkLowLevelKybd;    
HINSTANCE hInstance = GetModuleHandle(NULL);

// Install the low-level keyboard hook
hhkLowLevelKybd  = SetWindowsHookEx(WH_KEYBOARD_LL,
                LowLevelKeyboardProc,
                hInstance,
                NULL );

Next, have LowLevelKeyboardProc execute your routines in response to the ESC keyup:

_declspec(dllexport) LRESULT CALLBACK LowLevelKeyboardProc( int nCode, WPARAM wParam, LPARAM lParam)
{
    if (nCode == HC_ACTION)
    {
         PKBDLLHOOKSTRUCT p = ( PKBDLLHOOKSTRUCT ) lParam;
         switch (wParam)
         {
            case WM_KEYUP:
            case WM_SYSKEYUP:
                switch (p->vkCode)
                {
                   case 0x1B: //OR VK_ESCAPE
                       maxReached = false;
                       break;
                   default:
                       break;
                }
                break;
            default:
                break;
         }
     }
     return(CallNextHookEx( NULL, nCode, wParam, lParam ));
}