MFC Global keyboard hook

Question

How make application detect Kay press when application not in focus? [Solved] I need start timer on Insert key press and stop on press again when the application window not focused. can anyone show me source or some example MFC based? I know that MFC don't have that kind members, but how looks correct source implemented in MFC? How start timer by key press?

  // MainHamsterDlg.cpp : implementation file

        #include "stdafx.h"
        #include "MainHamsterDlg.h"

        // MainHamsterDlg dialog
        IMPLEMENT_DYNAMIC(MainHamsterDlg, CDialogEx)

        MainHamsterDlg::MainHamsterDlg(CWnd* pParent)
            : CDialogEx(MainHamsterDlg::IDD, pParent)
        {

        }

        void MainHamsterDlg::DoDataExchange(CDataExchange* pDX)
        {
            CDialogEx::DoDataExchange(pDX);
        }


        BEGIN_MESSAGE_MAP(MainHamsterDlg, CDialogEx)
            ON_WM_TIMER()
        END_MESSAGE_MAP()


        HHOOK _hook;
        KBDLLHOOKSTRUCT kbdStruct;

        LRESULT __stdcall HookCallback(int nCode, WPARAM wParam, LPARAM lParam)
        {
            if (nCode >= 0)
            {
                // the action is valid: HC_ACTION.
                if (wParam == WM_KEYUP)
                {
                    kbdStruct = *((KBDLLHOOKSTRUCT*)lParam);
                    // a key (non-system) is pressed.
                    if (kbdStruct.vkCode == VK_INSERT)
                    {
                       SetTimer(NULL, 0, 0, NULL); <<<----- this don't starts timer 
                    }
                }
            }
           return CallNextHookEx(_hook, nCode, wParam, lParam);
        }

        void SetHook()
        {
            if (!(_hook = SetWindowsHookEx(WH_KEYBOARD_LL, HookCallback, NULL, 0)))
            {
                MessageBox(NULL, "Failed to install hook!", "Error", MB_ICONERROR);
            }
        }

        void ReleaseHook()
        {
            UnhookWindowsHookEx(_hook);
        }

        BOOL MainHamsterDlg::OnInitDialog()
        { SetHook();

            //SetTimer(0, 0, NULL); <<<------- this starts timer 
            CDialogEx::OnInitDialog();

            return TRUE;
        }

        void MainHamsterDlg::OnTimer(UINT nIDEvent)
        {
        //do something
              CDialog::OnTimer(nIDEvent);
        }

Answer 1

you can use SetWindowsHookEx

This allows you to make global hooks for any callbacks.