KeyBd_Event question

[BOB MECHLER]

The following code sends a Ctrl-F to my callback but needs an additional press of the Control key to allow typing. If I unremark the last statement it doesn't send the Ctrl-F. What is the correct way to use KeyBd_Event to send a Ctrl-F.

Thanks,

Bob Mechler

              KeyBd_Event %VK_CONTROL, MapVirtualKey(%VK_CONTROL,0),0,0: SLEEP 0
              KeyBd_Event %VK_F,MapVirtualKey(%VK_F,0),0,0: SLEEP 0
              KeyBd_Event %VK_F,MapVirtualKey(%VK_F, 0), %KEYEVENTF_KEYUP, 0: SLEEP 0
              'KeyBd_Event %VK_CONTROL, MapVirtualKey(%VK_CONTROL, 0), %KEYEVENTF_KEYUP, 0: SLEEP 0

[Eddy Van Esch]

Bob,

'SendInput' is less critical what timing is concerned than 'KeyBd_Event'.
I suggest you try that instead.
This small sub sends a CTRL-ed key.

SendCTRLKey(%VK_F)

SUB SendCTRLKey(BYVAL kbvalue AS LONG)
    LOCAL inpAPI() AS INPUTAPI
    DIM inpAPI(0:3)

    inpAPI(0).dtype          = %INPUT_KEYBOARD  
    inpAPI(0).m.ki.wVk         = %VK_CONTROL    
    inpAPI(0).m.ki.dwFlags     = 0                               
    inpAPI(0).m.ki.wScan       = MAPVIRTUALKEY(%VK_CONTROL, 0)                

    
    inpAPI(1).dtype          = %INPUT_KEYBOARD  
    inpAPI(1).m.ki.wVk         = kbvalue             
    inpAPI(1).m.ki.dwFlags     = 0                
    inpAPI(1).m.ki.wScan       = MAPVIRTUALKEY(kbvalue, 0)                
                    
    inpAPI(2).dtype          = %INPUT_KEYBOARD   
    inpAPI(2).m.ki.wVk         = kbvalue             
    inpAPI(2).m.ki.dwFlags     = %KEYEVENTF_KEYUP  
    inpAPI(2).m.ki.wScan       = MAPVIRTUALKEY(kbvalue, 0)                

    inpAPI(3).dtype          = %INPUT_KEYBOARD   
    inpAPI(3).m.ki.wVk         = %VK_CONTROL
    inpAPI(3).m.ki.dwFlags     = %KEYEVENTF_KEYUP  
    inpAPI(3).m.ki.wScan       = MAPVIRTUALKEY(%VK_CONTROL, 0)                
              
    SendInput(4, inpAPI(0), SIZEOF(inpAPI(0)))

END SUB

Kind regards

[BOB MECHLER]

Nice code Eddie. I'm sure it works find in the standard situation. I think the keyboard hooking I'm doing is part of the problem. I've been trying to adapt the keyboard hook code from Egbert Zijlema to pass a Ctrl-F and then send a WM_COMMAND message to the desired control callback. See the second piece of code.

When I press Ctrl-F it fires the Add_Party_Button properly. If I trigger a Control-F via a menu item callback it doesn't work with the code I posted or your code. I probably have a %TRUE or %FALSE in the wrong place. All the code in Poffs does it the way I was doing it (with the last line unremmed out).

I probably need to use accelerators or keyboard hooking but not both on the same key combination.

FUNCTION KeyboardHook(BYVAL HookCode AS LONG, BYVAL wParam AS LONG, BYVAL lParam AS LONG) AS DWORD
LOCAL lShiftMode AS LONG
 FUNCTION = CallNextHookEx(hKeyboardHook, HookCode, wParam, lParam)

 IF HookCode = %HC_ACTION THEN
   IF ISFALSE(lParam AND &H80000000) THEN 'Key is released
     SELECT CASE wParam
       CASE %VK_F1 TO %VK_F12,%VK_RIGHT,%VK_LEFT
         'Send a custom message to our dialog
         IF ISTRUE(lParam AND &H20000000) THEN lShiftMode = %MOD_ALT      ' bit 29 (2^29) set: Alt-key is down
         IF (GetAsyncKeyState(%VK_CONTROL) AND &H8000) THEN _
                             lShiftMode = lShiftMode + %MOD_CONTROL      ' eventually add Ctrl
         IF (GetAsyncKeyState(%VK_SHIFT) AND &H8000) _
                          THEN lShiftMode = lShiftMode + %MOD_SHIFT      ' eventually add Shift
         PostMessage ghDlg(0), %HookedKeyboardMessage, wParam, lShiftMode'lParam
         FUNCTION = %TRUE 'If function is true, key will not be forwarded to dialog
       CASE %VK_F         
         'Send a custom message to our dialog
         IF ISTRUE(lParam AND &H20000000) THEN lShiftMode = %MOD_ALT      ' bit 29 (2^29) set: Alt-key is down
         IF (GetAsyncKeyState(%VK_CONTROL) AND &H8000) THEN _
                             lShiftMode = lShiftMode + %MOD_CONTROL      ' eventually add Ctrl
         IF (GetAsyncKeyState(%VK_SHIFT) AND &H8000) _
                          THEN lShiftMode = lShiftMode + %MOD_SHIFT      ' eventually add Shift
         IF lShiftMode <> 0 THEN                          
           PostMessage ghDlg(0), %HookedKeyboardMessage, wParam, lShiftMode   'lParam
           FUNCTION = %TRUE 'If function is true, key will not be forwarded to dialog
         ELSE  
           FUNCTION = %FALSE 'Allows a plain F to pass through to the dialog otherwise I couldn't type an F in a textbox 
         END IF  
     END SELECT 
   END IF
 END IF

END FUNCTION
'
'
'
   CASE %HookedKeyboardMessage
     SELECT CASE CBWPARAM
       CASE %VK_F 'This works fine if CTRL-F is typed but not if I use KEYBD_EVENT as in the previous post
         IF CBLPARAM = %MOD_CONTROL THEN
            DIALOG SEND CBHNDL, %WM_COMMAND, MAKDWD(%Find_Acct, %BN_CLICKED), GetDlgItem(CBHNDL, %Find_Acct)           
         END IF 
       CASE %VK_F1
       CASE %VK_F2
         CONTROL SEND CBHNDL, %tab_control, %TCM_GETCURSEL, 0, 0 TO tabhit 
	 SELECT CASE tabhit 'tabhit tells us which tab dialog is active
	   CASE 0
	   CASE 1
	   CASE 2
	   CASE 3
                    DIALOG SEND gHdlg(4), %WM_COMMAND, MAKDWD(%Add_Party_Button, %BN_CLICKED), GetDlgItem(gHdlg(4), %Add_Party_Button) 'F2 Add Party
	   CASE 4
	   CASE 5
	   CASE 6
	END SELECT  
       CASE %VK_F3,%VK_LEFT
          DIALOG SEND CBHNDL, %WM_COMMAND, MAKDWD(%b_PrevRec, %BN_CLICKED), GetDlgItem(CBHNDL, %b_PrevRec)
       CASE %VK_F4,%VK_RIGHT
          DIALOG SEND CBHNDL, %WM_COMMAND, MAKDWD(%b_NextRec, %BN_CLICKED), GetDlgItem(CBHNDL, %b_NextRec)
       CASE %VK_F5
       CASE %VK_F6
          DIALOG SEND CBHNDL, %WM_COMMAND, MAKDWD(%b_NameLookup, %BN_CLICKED), GetDlgItem(CBHNDL, %b_NameLookup)                
       CASE %VK_F10
         
     END SELECT

[BOB MECHLER]

Instead of generating a Ctrl-F when I already had this key hooked to send a message to a control, I decided to just send the message from the menu item callback instead of the Ctrl-F. The Ctrl-F on the menu item serves to remind the user of the keyboard shortcut.

Bob Mechler

[Michael Mattias]

Also, keyboard input - real or faked - goes to the window with the keyboard focus. If something has grabbed the focus (eg a MSGBOX with focus not restored) then that input goes "somewhere else."

But I think you are on a better track to cut out the multiple methods of making something happen.. and better still to to send the matching WM_COMMAND command message to yourself, keeping control out of foreign hands.

[BOB MECHLER]

Are accelerators like those created in PB Forms to work with menus really just a more convenient way of creating a keyboard hook? They seem so similar in how they work. I detached the menu code and the accelerators seemed to still work just like a keyboard hook. I'l a little confused about when to use which method. The Alt-A where the caption of a button is &Add Record seems very sound. The menu builder seems to prefer Ctrl- keys.

Bob Mechler

[Michael Mattias]

The difference is, with a hook procedure - if global (systemwide) in implementation - striking the "magic key" can be made to send a signal or message to any process regardless of the current active process or who has the keyboard focus, whereas accelerators only pick off keystrokes when the target process is the current process.

Darned, I'm afraid I've given another answer which is "application-specific." I sure seem to do that a lot, don't I?

MCM