Link to home
Start Free TrialLog in
Avatar of eugeneng
eugeneng

asked on

how do I trap every single WM_KEYDOWN msg window receive ?

I want to write a program which will trap every key stroke, so how do I trap every key down message that window95 receive (even when my program is not focused)
Avatar of naveenkohli
naveenkohli
For this you will need to make use of Hooks. Here is some stuff from Microsoft's online documentation.. For more on this you can have look at msdn resources.. :))

good Luck!


*********************************************
Monitoring System Events
The following example uses a variety of thread-specific hook procedures to monitor the system for events affecting a thread. It demonstrates how to process events for the following types of hook procedures:

WH_CALLWNDPROC
WH_CBT
WH_DEBUG
WH_GETMESSAGE
WH_KEYBOARD
WH_MOUSE
WH_MSGFILTER

The user can install and remove a hook procedure by using the menu. When a hook procedure is installed and an event that is monitored by the procedure occurs, the procedure writes information about the event to the client area of the application's main window.

#define NUMHOOKS 7
 
// Global variables
 
typedef struct _MYHOOKDATA
{
    int nType;
    HOOKPROC hkprc;
    HHOOK hhook;
} MYHOOKDATA;
 
MYHOOKDATA myhookdata[NUMHOOKS];
 
LRESULT WINAPI MainWndProc(HWND hwndMain, UINT uMsg, WPARAM wParam,
    LPARAM lParam)
{
    static BOOL afHooks[NUMHOOKS];
    int index;
    static HMENU hmenu;
 
    switch (uMsg)
    {
        case WM_CREATE:
 
            // Save the menu handle.
 
            hmenu = GetMenu(hwndMain);
 
            // Initialize structures with hook data. The menu-item
            // identifiers are defined as 0 through 6 in the
            // header file. They can be used to identify array
            // elements both here and during the WM_COMMAND
            // message.
 
            myhookdata[IDM_CALLWNDPROC].nType = WH_CALLWNDPROC;
            myhookdata[IDM_CALLWNDPROC].hkprc = CallWndProc;
            myhookdata[IDM_CBT].nType = WH_CBT;
            myhookdata[IDM_CBT].hkprc = CBTProc;
            myhookdata[IDM_DEBUG].nType = WH_DEBUG;
            myhookdata[IDM_DEBUG].hkprc = DebugProc;
            myhookdata[IDM_GETMESSAGE].nType = WH_GETMESSAGE;
            myhookdata[IDM_GETMESSAGE].hkprc = GetMsgProc;
            myhookdata[IDM_KEYBOARD].nType = WH_KEYBOARD;
            myhookdata[IDM_KEYBOARD].hkprc = KeyboardProc;
            myhookdata[IDM_MOUSE].nType = WH_MOUSE;
            myhookdata[IDM_MOUSE].hkprc = MouseProc;
            myhookdata[IDM_MSGFILTER].nType = WH_MSGFILTER;
            myhookdata[IDM_MSGFILTER].hkprc = MessageProc;
 
            // Initialize all flags in the array to FALSE.
 
            memset(afHooks, FALSE, sizeof(afHooks));
 
            return 0;
 
        case WM_COMMAND:
            switch (LOWORD(wParam))
            {
                 // The user selected a hook command from the menu.
 
                case IDM_CALLWNDPROC:
                case IDM_CBT:
                case IDM_DEBUG:
                case IDM_GETMESSAGE:
                case IDM_KEYBOARD:
                case IDM_MOUSE:
                case IDM_MSGFILTER:
 
                    // Use the menu-item identifier as an index
                    // into the array of structures with hook data.
 
                    index = LOWORD(wParam);
 
                    // If the selected type of hook procedure isn't
                    // installed yet, install it and check the
                    // associated menu item.
 
                    if (!afHooks[index])
                    {
                        myhookdata[index].hhook = SetWindowsHookEx(
                            myhookdata[index].nType,
                            myhookdata[index].hkprc,
                            (HINSTANCE) NULL, GetCurrentThreadId());
                        CheckMenuItem(hmenu, index,
                            MF_BYCOMMAND | MF_CHECKED);
                        afHooks[index] = TRUE;
                    }
 
                    // If the selected type of hook procedure is
                    // already installed, remove it and remove the
                    // check mark from the associated menu item.
 
                    else
                    {
                        UnhookWindowsHookEx(myhookdata[index].hhook);
                        CheckMenuItem(hmenu, index,
                            MF_BYCOMMAND | MF_UNCHECKED);
                        afHooks[index] = FALSE;
                    }
 
                default:
                    return (DefWindowProc(hwndMain, uMsg, wParam,
                        lParam));
            }
            break;
 
            //
            // Process other messages.
            //
 
        default:
            return DefWindowProc(hwndMain, uMsg, wParam, lParam);
    }
    return NULL;
}
 
/****************************************************************
  WH_CALLWNDPROC hook procedure
 ****************************************************************/
 
LRESULT WINAPI CallWndProc(int nCode, WPARAM wParam, LPARAM lParam)
{
    CHAR szCWPBuf[256];
    CHAR szMsg[16];
    HDC hdc;
    static int c = 0;
    int cch;
 
    if (nCode < 0)  // do not process message
        return CallNextHookEx(myhookdata[CALLWNDPROC].hhook, nCode,
                wParam, lParam);
 
    // Call an application-defined function that converts a message
    // constant to a string and copies it to a buffer.
 
    LookUpTheMessage((PMSG) lParam, szMsg);
 
    hdc = GetDC(hwndMain);
 
    switch (nCode)
    {
        case HC_ACTION:
            cch = wsprintf(szCWPBuf,
               "CALLWNDPROC - tsk: %ld, msg: %s, %d times   ",
                wParam, szMsg, c++);
            TextOut(hdc, 2, 15, szCWPBuf, cch);
            break;
 
        default:
            break;
    }
 
    ReleaseDC(hwndMain, hdc);
    return CallNextHookEx(myhookdata[CALLWNDPROC].hhook, nCode,
        wParam, lParam);
}
 
/****************************************************************
  WH_GETMESSAGE hook procedure
 ****************************************************************/
 
LRESULT CALLBACK GetMsgProc(int nCode, WPARAM wParam, LPARAM lParam)
{
    CHAR szMSGBuf[256];
    CHAR szRem[16];
    CHAR szMsg[16];
    HDC hdc;
    static int c = 0;
    int cch;
 
    if (nCode < 0) // do not process message
        return CallNextHookEx(myhookdata[GETMESSAGE].hhook, nCode,
            wParam, lParam);
 
    switch (nCode)
    {
        case HC_ACTION:
            switch (wParam)
            {
                case PM_REMOVE:
                    lstrcpy(szRem, "PM_REMOVE");
                    break;
 
                case PM_NOREMOVE:
                    lstrcpy(szRem, "PM_NOREMOVE");
                    break;
 
                default:
                    lstrcpy(szRem, "Unknown");
                    break;
            }
 
            // Call an application-defined function that converts a
            // message constant to a string and copies it to a
            // buffer.
 
            LookUpTheMessage((PMSG) lParam, szMsg);
 
            hdc = GetDC(hwndMain);
            cch = wsprintf(szMSGBuf,
                "GETMESSAGE - wParam: %s, msg: %s, %d times   ",
                szRem, szMsg, c++);
            TextOut(hdc, 2, 35, szMSGBuf, cch);
            break;
 
        default:
            break;
    }
 
    ReleaseDC(hwndMain, hdc);
    return CallNextHookEx(myhookdata[GETMESSAGE].hhook, nCode,
        wParam, lParam);
}
 
/****************************************************************
  WH_DEBUG hook procedure
 ****************************************************************/
 
LRESULT CALLBACK DebugProc(int nCode, WPARAM wParam, LPARAM lParam)
{
    CHAR szBuf[128];
    HDC hdc;
    static int c = 0;
    int cch;
 
    if (nCode < 0)  // do not process message
        return CallNextHookEx(myhookdata[DEBUG].hhook, nCode,
            wParam, lParam);
 
    hdc = GetDC(hwndMain);
 
    switch (nCode)
    {
        case HC_ACTION:
            cch = wsprintf(szBuf,
                "DEBUG - nCode: %d, tsk: %ld, %d times   ",
                nCode,wParam, c++);
            TextOut(hdc, 2, 55, szBuf, cch);
            break;
 
        default:
            break;
    }
 
    ReleaseDC(hwndMain, hdc);
    return CallNextHookEx(myhookdata[DEBUG].hhook, nCode, wParam,
        lParam);
}
 
/****************************************************************
  WH_CBT hook procedure
 ****************************************************************/
 
LRESULT CALLBACK CBTProc(int nCode, WPARAM wParam, LPARAM lParam)
{
    CHAR szBuf[128];
    CHAR szCode[128];
    HDC hdc;
    static int c = 0;
    int cch;
 
    if (nCode < 0)  // do not process message
        return CallNextHookEx(myhookdata[CBT].hhook, nCode, wParam,
            lParam);
 
    hdc = GetDC(hwndMain);
 
    switch (nCode)
    {
        case HCBT_ACTIVATE:
            lstrcpy(szCode, "HCBT_ACTIVATE");
            break;
 
        case HCBT_CLICKSKIPPED:
            lstrcpy(szCode, "HCBT_CLICKSKIPPED");
            break;
 
        case HCBT_CREATEWND:
            lstrcpy(szCode, "HCBT_CREATEWND");
            break;
 
        case HCBT_DESTROYWND:
            lstrcpy(szCode, "HCBT_DESTROYWND");
            break;
 
        case HCBT_KEYSKIPPED:
            lstrcpy(szCode, "HCBT_KEYSKIPPED");
            break;
 
        case HCBT_MINMAX:
            lstrcpy(szCode, "HCBT_MINMAX");
            break;
 
        case HCBT_MOVESIZE:
            lstrcpy(szCode, "HCBT_MOVESIZE");
            break;
 
        case HCBT_QS:
            lstrcpy(szCode, "HCBT_QS");
            break;
 
        case HCBT_SETFOCUS:
            lstrcpy(szCode, "HCBT_SETFOCUS");
            break;
 
        case HCBT_SYSCOMMAND:
            lstrcpy(szCode, "HCBT_SYSCOMMAND");
            break;
 
        default:
            lstrcpy(szCode, "Unknown");
            break;
    }
 
    cch = wsprintf(szBuf, "CBT - nCode: %s, tsk: %ld, %d times   ",
        szCode, wParam, c++);
    TextOut(hdc, 2, 75, szBuf, cch);
    ReleaseDC(hwndMain, hdc);
    return CallNextHookEx(myhookdata[CBT].hhook, nCode, wParam,
        lParam);
}
 
/****************************************************************
  WH_MOUSE hook procedure
 ****************************************************************/
 
LRESULT CALLBACK MouseProc(int nCode, WPARAM wParam, LPARAM lParam)
{
    CHAR szBuf[128];
    CHAR szMsg[16];
    HDC hdc;
    static int c = 0;
    int cch;
 
    if (nCode < 0)  // do not process the message
        return CallNextHookEx(myhookdata[MOUSE].hhook, nCode,
            wParam, lParam);
 
    // Call an application-defined function that converts a message
    // constant to a string and copies it to a buffer.
 
    LookUpTheMessage((PMSG) lParam, szMsg);
 
    hdc = GetDC(hwndMain);
    cch = wsprintf(szBuf,
        "MOUSE - nCode: %d, msg: %s, x: %d, y: %d, %d times   ",
        nCode, szMsg, LOWORD(lParam), HIWORD(lParam), c++);
    TextOut(hdc, 2, 95, szBuf, cch);
    ReleaseDC(hwndMain, hdc);
    return CallNextHookEx(myhookdata[MOUSE].hhook, nCode, wParam,
        lParam);
}
 
/****************************************************************
  WH_KEYBOARD hook procedure
 ****************************************************************/
 
LRESULT CALLBACK KeyboardProc(int nCode, WPARAM wParam, LPARAM lParam)
{
    CHAR szBuf[128];
    HDC hdc;
    static int c = 0;
    int cch;
 
    if (nCode < 0)  // do not process message
        return CallNextHookEx(myhookdata[KEYBOARD].hhook, nCode,
            wParam, lParam);
 
    hdc = GetDC(hwndMain);
    cch = wsprintf(szBuf, "KEYBOARD - nCode: %d, vk: %d, %d times ",
        nCode, wParam, c++);
    TextOut(hdc, 2, 115, szBuf, cch);
    ReleaseDC(hwndMain, hdc);
    return CallNextHookEx(myhookdata[KEYBOARD].hhook, nCode, wParam,
        lParam);
}
 
/****************************************************************
  WH_MSGFILTER hook procedure
 ****************************************************************/
 
LRESULT CALLBACK MessageProc(int nCode, WPARAM wParam, LPARAM lParam)
{
    CHAR szBuf[128];
    CHAR szMsg[16];
    CHAR szCode[32];
    HDC hdc;
    static int c = 0;
    int cch;
 
    if (nCode < 0)  // do not process message
        return CallNextHookEx(myhookdata[MSGFILTER].hhook, nCode,
            wParam, lParam);
 
    switch (nCode)
    {
        case MSGF_DIALOGBOX:
            lstrcpy(szCode, "MSGF_DIALOGBOX");
            break;
 
        case MSGF_MENU:
            lstrcpy(szCode, "MSGF_MENU");
            break;
 
        case MSGF_SCROLLBAR:
            lstrcpy(szCode, "MSGF_SCROLLBAR");
            break;
 
        default:
            wsprintf(szCode, "Unknown: %d", nCode);
            break;
    }
 
    // Call an application-defined function that converts a message
    // constant to a string and copies it to a buffer.
 
    LookUpTheMessage((PMSG) lParam, szMsg);
 
    hdc = GetDC(hwndMain);
    cch = wsprintf(szBuf,
        "MSGFILTER  nCode: %s, msg: %s, %d times    ",
        szCode, szMsg, c++);
    TextOut(hdc, 2, 135, szBuf, cch);
    ReleaseDC(hwndMain, hdc);
    return CallNextHookEx(myhookdata[MSGFILTER].hhook, nCode,
        wParam, lParam);
}


Avatar of chensu
chensu
Flag of Canada image
SAMPLE: KbHook.exe Demos Keyboard Hook Function Keyboard Filter
http://support.microsoft.com/support/kb/articles/q66/9/89.asp

SAMPLE: KBHook2.exe Demonstrates Using a WH_KEYBOARD Hook
http://support.microsoft.com/support/kb/articles/q81/3/34.asp
Avatar of eugeneng
eugeneng

ASKER

is there any way to activate a program without double click on it, for example, when the "Start" button is pressed, when a key is depressed, or when the system time has met a specific time ?
Avatar of chensu
chensu
Flag of Canada image
Call the ShellExecute function.
ASKER CERTIFIED SOLUTION
Avatar of Buddah1
Buddah1
Link to home
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
Start Free Trial