Is there a way to stop a reboot/shutdown?

[Mike Doty]

This code might slow down a reboot, but won't prevent it.
Using DDT with PB 9 on XP SP3. If TCP transfer is in progress
it is halted (which is what I'm trying to complete.)

CALLBACK FUNCTION MyCallBack()
    SELECT CASE AS LONG CBMSG
         CASE %WM_QUERYENDSESSION
             PostQuitMessage 0
             FUNCTION = %TRUE     ' don't allow default action
             'BEEP
             'PostQuitMessage 0
             'PostMessage CBHNDL, %WM_USER + 2049, 0, 0
              'DoNotEnd

[Dave Biggs]

This might help..

http://www.powerbasic.com/support/pbforums/showthread.php?p=300982&highlight=WM_QUERYENDSESSION#post300982

[Michael Mattias]

CASE %WM_QUERYENDSESSION
             PostQuitMessage 0

PostQuitMessag()? Here?

"Normally " you'd post WM_QUIT on WM_DESTROY. That might be causing you some issues.

For that matter if this is the callback for a MODAL dialog (code not shown) then PostQuitmessage is not required at all.

[Mike Doty]

Dave,
Your code works. It displays the first message box for 3-seconds which is better than my unpredictable results. It then allows not allowing
the reboot. I will try the same method and get back. I'm not sure that
my TCP session will be trashed in the process, but at least I can notify
the user it wasn't completed.

Michael DDT 9 modal.

[Mike Doty]

Can End Program dialog be closed with PostMessage?

I'm getting the handle to the End Program dialog and sending
x = PostMessage(gShutDownHandle, %WM_QUIT,0,0) 'returns 1
'This doesn't close the End Program dialog. How would it be done?
'Is %WM_QUIT the correct message to send
'Is this the correct windows handle?

Tried modifying the code to shutdown NOTEPAD and it does shut NOTEPAD so
the code might be close to ending the shutdown dialog?

Tried SendMessage without luck, too.
I'll try sending ALT+F4 next.

CALLBACK FUNCTION MyCallBack()
  LOCAL x AS LONG
    SELECT CASE AS LONG CBMSG
      CASE %WM_QUERYENDSESSION
        SLEEP 10000  'wait for end program dialog
        EnumWindows CODEPTR(EnumWindowsProc), 0
        IF gShutDownHandle THEN
           x = PostMessage(gShutDownHandle, %WM_QUIT,0,0)
           ? "Result was" + STR$(x) 'returns 1
        END IF
        ? "Here as a safeguard" 
 
FUNCTION EnumWindowsProc(BYVAL lHandle AS LONG, BYVAL lNotUsed AS LONG) AS LONG
  LOCAL result AS LONG
  gsTitle = STRING$(256,0)
  GetWindowText lHandle, BYVAL STRPTR(gsTitle), 256
  gsTitle = EXTRACT$(gsTitle,CHR$(0))
  IF UCASE$(LEFT$(gsTitle,11)) = "END PROGRAM" THEN
    gShutDownHandle = lHandle
    result = PostMessage(lHandle, %WM_QUIT,0,0)  'returns 1
    EXIT FUNCTION
  END IF
  FUNCTION = 1  'keep looking while 1
END FUNCTION

[Michael Mattias]

>I'm getting the handle to the End Program dialog and sending...

???
The shutdown sequence is ended...

The WM_QUERYENDSESSION message is sent when the user chooses to end the session or when an application calls the ExitWindows function. If any application returns zero, the session is not ended. The system stops sending WM_QUERYENDSESSION messages as soon as one application returns zero.

I don't understand what you are trying to accomplish here. Returning zero in response to WM_QUERYENDSESSION should be all you need to do to terminate the shutdown sequence.

If other applications choose to use another mechanism...

      CASE %WM_QUERYENDSESSION
         bQuit =  ISTRUE (MSGBOX (question) = %IDYES )
         FUNCTION =  ISTRUE (bQuit) 
         EXIT FUNCTION

... there is nothing you can do about that unless you can respond the the message box or other prompt.

Only thing I can think of which might be interfering with this would be, maybe your process needs certain permissions to "terminate the Windows' shutdown sequence"

[Mike Doty]

Stop reboot - also closes End Program window

*** SOLVED PROBLEM This code works correctly. Thread may be closed. Thank you. ***
This code is to prevent reboot if say a file download is in progress.
This sniplet shows a global is set so reboot should not be allowed.

CASE %WM_QUERYENDSESSION
  IF gBusy THEN
    SLEEP 8000 'normally between 5 and 6 seconds
    DIALOG DOEVENTS
    result = EnumWindows(CODEPTR(EnumWindowsProc), 0)
  END IF 
 
EnumWindows uses this logic:
IF UCASE$(LEFT$(zTitle,11)) = "END PROGRAM" THEN
    PostMessage(lHandle, %WM_CLOSE,0,0) 'WM_QUIT doesn't work

'Here is a completed working test program

#PBFORMS CREATED V1.52
#COMPILE EXE
#DIM ALL
#PBFORMS BEGIN INCLUDES
#IF NOT %DEF(%WINAPI)
    #INCLUDE "WIN32API.INC"
#ENDIF
#PBFORMS END INCLUDES
#PBFORMS BEGIN CONSTANTS
%IDD_DIALOG1 = 101
#PBFORMS END CONSTANTS
DECLARE CALLBACK FUNCTION ShowDIALOG1Proc()
DECLARE FUNCTION ShowDIALOG1(BYVAL hParent AS DWORD) AS LONG
#PBFORMS DECLARATIONS
FUNCTION PBMAIN()
    ShowDIALOG1 %HWND_DESKTOP
END FUNCTION
CALLBACK FUNCTION ShowDIALOG1Proc()
    SELECT CASE AS LONG CBMSG
        CASE %WM_QUERYENDSESSION
          SLEEP 8000  'normally between 5 and 6 seconds
          EnumWindows CODEPTR(EnumWindowsProc), 0
 
        CASE %WM_INITDIALOG
            ' Initialization handler
        CASE %WM_NCACTIVATE
            STATIC hWndSaveFocus AS DWORD
            IF ISFALSE CBWPARAM THEN
                ' Save control focus
                hWndSaveFocus = GetFocus()
            ELSEIF hWndSaveFocus THEN
                ' Restore control focus
                SetFocus(hWndSaveFocus)
                hWndSaveFocus = 0
            END IF
        CASE %WM_COMMAND
            ' Process control notifications
            SELECT CASE AS LONG CBCTL
            END SELECT
    END SELECT
END FUNCTION
'------------------------------------------------------------------------------
'------------------------------------------------------------------------------
'   ** Dialogs **
'------------------------------------------------------------------------------
FUNCTION ShowDIALOG1(BYVAL hParent AS DWORD) AS LONG
    LOCAL lRslt AS LONG
#PBFORMS BEGIN DIALOG %IDD_DIALOG1->->
    LOCAL hDlg  AS DWORD
    DIALOG NEW hParent, "%WM_QUERYENDSESSION NOT ALLOWING REBOOT", 206, 164, 201, 121, %WS_POPUP OR _
        %WS_BORDER OR %WS_DLGFRAME OR %WS_SYSMENU OR %WS_CLIPSIBLINGS OR _
        %WS_VISIBLE OR %DS_MODALFRAME OR %DS_3DLOOK OR %DS_NOFAILCREATE OR _
        %DS_SETFONT, %WS_EX_CONTROLPARENT OR %WS_EX_LEFT OR _
        %WS_EX_LTRREADING OR %WS_EX_RIGHTSCROLLBAR, TO hDlg
#PBFORMS END DIALOG
    DIALOG SHOW MODAL hDlg, CALL ShowDIALOG1Proc TO lRslt
#PBFORMS BEGIN CLEANUP %IDD_DIALOG1
#PBFORMS END CLEANUP
    FUNCTION = lRslt
END FUNCTION
'------------------------------------------------------------------------------
FUNCTION EnumWindowsProc(BYVAL lHandle AS LONG, BYVAL lNotUsed AS LONG) AS LONG
  LOCAL result AS LONG
  LOCAL zTitle AS ASCIIZ * 256
  GetWindowText lHandle, zTitle, 256
  zTitle  = EXTRACT$(zTitle,$NUL)
  IF UCASE$(LEFT$(zTitle,11)) = "END PROGRAM" THEN
    PostMessage(lHandle, %WM_CLOSE,0,0) 'WM_QUIT doesn't work with End Program shutdown
    SLEEP 10   'required
    DIALOG DOEVENTS
    FUNCTION = 0
    EXIT FUNCTION
  END IF
  FUNCTION = 1  'keep looking or signals done
END FUNCTION

[Michael Mattias]

>This code is to prevent reboot if say a file download is in progress.


Now I am really confused.

If the file download is in your program and you have a global variable indicating a download is in progress, then all you should have to do on WM_QUERYENDSESSION is check that variable and exit with %TRUE or %FALSE as appropriate.

If some other program is NOT checking WM_QUERYENDSESSION during its file downloads, I'd get a new download program.

MCM

[Mike Doty]

I posted code tested with DDT. PB 9 and XP SP3.
What did you test with?
Just exiting that way does not stop shutdown.

[Dave Biggs]

Mike,

I fixed the sample code http://www.powerbasic.com/support/pb...ION#post300982 so that it doesn't close the message box after 3seconds.

If you add these three functions to your TCP program and insert the Case statements into it's DialogProc that might be all you need?

%SHTDN_REASON_FLAG_USER_DEFINED = &H40000000
 
FUNCTION IsNt () AS LONG
 LOCAL tOsVersion AS OSVERSIONINFO
  tOsVersion.dwOSVersionInfoSize = SIZEOF(tOsVersion)
  IF GetVersionEx(tOsVersion) THEN
      FUNCTION = (tOsVersion.dwPlatformId = %VER_PLATFORM_WIN32_NT)
  END IF
END FUNCTION
'------------------/IsNt
 
FUNCTION AdjustToken () AS LONG
 LOCAL hToken       AS DWORD
 LOCAL tokenProcess AS TOKEN_PRIVILEGES
    ' Get the privilege token for this process. - keep in hToken
  IF ISFALSE OpenProcessToken(GetCurrentProcess(), %TOKEN_ADJUST_PRIVILEGES OR %TOKEN_QUERY, hToken) THEN
    EXIT FUNCTION
  END IF
    ' Get the value of the shutdown privilege.
  IF LookupPrivilegeValue(BYVAL %NULL, "SeShutdownPrivilege", tokenProcess.Privileges(0).pLuid) THEN
    ' Enable the shutdown privilege for this process.
    tokenProcess.PrivilegeCount           = 1
    tokenProcess.Privileges(0).Attributes = %SE_PRIVILEGE_ENABLED
    FUNCTION = AdjustTokenPrivileges(hToken, %FALSE, tokenProcess, 0, BYVAL %NULL, BYVAL %NULL)
  END IF
 CloseHandle hToken
END FUNCTION
'------------------/AdjustTken
 
FUNCTION ResumeShutDown(BYVAL LogOff AS LONG) AS LONG
  IF IsNT() THEN
    IF ISFALSE AdjustToken() THEN
      MSGBOX "Could not obtain shutdown privilege."
      EXIT FUNCTION
    END IF
  END IF
    ' If you're using Windows XP or later, you may want to provide a shutdown
    ' reason code in the second parameter. See the Reason.inc file for codes.
    ' The major reason code should be ORed with the minor reason code.
    ' eg %SHTDN_REASON_FLAG_USER_DEFINED  = &H40000000
  IF LogOff = 0 THEN
    IF ISFALSE ExitWindowsEx(%EWX_SHUTDOWN OR %EWX_FORCEIFHUNG, %SHTDN_REASON_FLAG_USER_DEFINED) THEN
        MSGBOX "Shutdown failed."
    END IF
  ELSE
    IF ISFALSE ExitWindowsEx(%EWX_LOGOFF, 0) THEN
        MSGBOX "Shutdown failed."
    END IF
  END IF
END FUNCTION
'------------------/ResumeShutDown
 
CALLBACK FUNCTION DlgProc
  DIM Res AS LONG
  STATIC ThisProc, LogOff AS Long 
'..
  SELECT CASE AS LONG CbMsg
'..
 
      CASE %WM_QUERYENDSESSION
        IF ThisProc = 0 THEN
          ThisProc = %TRUE          ' Test for resume shutdown
          LogOff = IIF(CblParam AND %ENDSESSION_LOGOFF = %ENDSESSION_LOGOFF, 1, 0)
          PostMessage CbHndl, %WM_USER + 1000, 0, 0
          FUNCTION = 0              ' Stop the shutdown process
          EXIT FUNCTION
        END IF
 
      CASE %WM_USER + 1000
        MSGBOX TIME$ & ": Prevented ShutDown."
 
        ' Here you could wait for your TCP thread to end...
 
        Res = MSGBOX ("Resume Shutdown / LogOff?", %MB_YESNO OR %MB_SYSTEMMODAL _    ' / logoff
                 OR %MB_ICONWARNING OR %MB_DEFBUTTON2, "Ready to quit?")
        IF Res = %IDYES THEN
          ResumeShutDown (LogOff)
        ELSE
          ThisProc = 0
          LogOff = 0
 
  END SELECT
END FUNCTION
'------------------/DlgProc

That will enable the shutdown privilege too, if required.

[Mike Doty]

Thanks, Dave. I have working code and posted it above.

[Dave Biggs]

Glad you have what you need Mike but FYI your code didn't prevent my PC (WinXP Home) from rebooting.
I don't have a window with "END PROGRAM" in the title though..

[Mike Doty]

Good catch.
I'll add some code that uses the current running program title and test with Vista while at it.