Detecting system shutdown or logoff - windows

Question

How can I detect when a system is shutting down or logging off with AutoIt?
I need to run a function if the computer is shutdown or logged off while my script is still running.

Answer 1

You need to handle the Message WM_QUERYENDSESSION
Sample Code:
; Define Windows Message Codes
$WM_QUERYENDSESSION = 0x11
; Define Callback Parameter Codes
$ENDSESSION_CLOSEAPP = 0x00000001
$ENDSESSION_CRITICAL = 0x40000000
$ENDSESSION_LOGOFF = 0x80000000
; Register a Callback on the Message to the Function "onShutDown"
GUIRegisterMsg($WM_QUERYENDSESSION, "onShutDown")
; #FUNCTION# ========================================================
; Name...........: onShutDown Example Function
; Description ...: Application receives the WM_QUERYENDSESSION message
;
; Parameters ....:
; $hWndGUI - A handle to the window
; $MsgID - The WM_QUERYENDSESSION identifier
; $wParam - This parameter is reserved for future use
; $lParam - This parameter can be one or more of the following values.
; |0 - The system is shutting down or restarting
; (it is not possible to determine which event is occurring)
; |$ENDSESSION_CLOSEAPP - Application is using a ressource or file that needs to be freed
; |$ENDSESSION_CRITICAL - Application is forced to shut down
; |$ENDSESSION_LOGOFF - The user is logging off
;
; Return values .:
; |True - Allow to Shutdown
; |False - Prevent Shutdown
; Remarks .......: Applications should respect the user's intentions and return TRUE. By default any application returns **TRUE** for this message.
; If shutting down would corrupt the system or media that is being burned, the application can return **FALSE**.
; However, it is good practice to respect the user's actions.
;
Func onShutDown($hWndGUI, $MsgID, $wParam, $lParam)
Return True ; allow Shutdown ( or return "False" to prevent Shutdown )
EndFunc
Also See : List of Windows Message Codes

Answer 2

You can implement OnAutoItExitRegister() in such a way that you can assume the PC is shutting down.
OnAutoItExitRegister("DetectShutdown")
GUICreate("My GUI") ; will create a dialog box that when displayed is centered
GUISetState(#SW_SHOW) ; will display an empty dialog box
; Run the GUI until the dialog is closed
While True
$msg = GUIGetMsg()
If $msg = $GUI_EVENT_CLOSE Then
OnAutoItExitUnRegister("DetectShutdown")
Exit
EndIf
WEnd
Func DetectShutdown()
MsgBox(0, "", "Shutdown Detected!")
EndFunc

Answer 3

How can I detect when a system is shutting down or logging off with AutoIt?
As per Documentation - Function Reference - OnAutoItExitRegister() :
The mode of exit can be retrieved with #exitMethod.
Also detects user logoff and Windows shutdown.
I need to run a function if the computer is shutdown or logged off while my script is still running.
Example (determination of-, and reaction to exit methods):
#include <AutoItConstants.au3>; #exitMethod constants.
Global Enum $EXIT_OK, _
$EXIT_ONAUTOITEXITREGISTER, _
$EXIT_HOTKEYSET
Global Const $g_iDelayMain = 250
Global Const $g_iDelayExit = 1000 * 5
Global Const $g_sKeyExit = '{ESC}'
Global Const $g_sConsole = '%s-%s-%s %s:%s:%s.%s - #exitCode = %i (%s) #exitMethod = %i (%s)\n'
Global Const $g_aExit = [ _
'OK', _
'OnAutoItExitRegister() failed', _
'HotKeySet() failed' _
]
Global Const $g_aMethod = [ _
'end of script reached', _
'Exit function executed', _
'systray exit function activated', _
'Windows logoff', _
'Windows shutdown' _
]
Global $g_bStateExit = False
Main()
Func Main()
If Not OnAutoItExitRegister('_ReportExit') Then Exit $EXIT_ONAUTOITEXITREGISTER
If Not HotKeySet($g_sKeyExit, 'SetStateExit') Then Exit $EXIT_HOTKEYSET
While Not $g_bStateExit
Sleep($g_iDelayMain)
WEnd
Exit $EXIT_OK
EndFunc
Func _ReportExit()
Local Const $sLine = StringFormat($g_sConsole, _
#YEAR, #MON, #MDAY, #HOUR, #MIN, #SEC, #MSEC, _
#exitCode, $g_aExit[#exitCode], _
#exitMethod, $g_aMethod[#exitMethod] _
)
ConsoleWrite($sLine)
Sleep($g_iDelayExit)
Switch #exitMethod
; Case $EXITCLOSE_NORMAL
; Your code here.
; Case $EXITCLOSE_BYEXIT
; Your code here.
; Case $EXITCLOSE_BYCLICK
; Your code here.
Case $EXITCLOSE_BYLOGOFF
; Your code here.
Case $EXITCLOSE_BYSHUTDOWN
; Your code here.
EndSwitch
EndFunc
Func SetStateExit()
$g_bStateExit = True
EndFunc