WinCE

If you want to monitor system wide keyboard events from an application, then we need to use keyboard hooking using the SetWindowsHookEx & UnhookWindowsHookEx functions. Since we need a system wide hook, we need to place the callback functions in a DLL.

typedef struct {
 DWORD vkCode;
 DWORD scanCode;
 DWORD flags;
 DWORD time;
 ULONG_PTR dwExtraInfo;
} KBDLLHOOKSTRUCT, *PKBDLLHOOKSTRUCT;
.....

VOID InitHook ()
{
 .....
 SetWindowsHookEx(WH_KEYBOARD_LL,hookproc,hinstance,NULL);
 .....
}
....
HOOKDLL_API LRESULT CALLBACK hookproc(int ncode,WPARAM wparam,LPARAM lparam)
{
UINT uMsg = 0;
if(ncode>=0)
{
   if((lparam & 0x80000000) == 0x00000000)//Check whether key was pressed(not released).
   {
      switch((((KBDLLHOOKSTRUCT*)lparam)->vkCode))
      {
         case VK_F1:
            RETAILMSG(1,(TEXT("TRAPPED, F1\r\n")));
            uMsg = WM_USER+755;
            break;

         case VK_F2:
            RETAILMSG(1,(TEXT("TRAPPED, F2\r\n")));
            uMsg = WM_USER+756;
            break;

         case VK_F3:
            RETAILMSG(1,(TEXT("TRAPPED, F3\r\n")));
            uMsg = WM_USER+757;
            break;

         case VK_F4:
            RETAILMSG(1,(TEXT("TRAPPED, F4\r\n")));
            uMsg = WM_USER+758;
            break;
      }

   }
}
return ( CallNextHookEx(hook,ncode,wparam,lparam) );//pass control to next hook in the hook chain.
}

But in Wince 6.0, these APIs have been removed, but is still present in coredll. Hence, they can be accessed using LoadLibrary and GetProcAddress functions.


N.B: Special Thanks Prathamesh S Kulkarni on his article on keyboard hooking in code project.