Hook to prevent window from closing

[MrCreatoR]

Hi,

I am trying to set a hook (by looking at other similar hooks) for specific window, to prevent a closing of that window (minimize it instead).

This is what i have so far:

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#include <GUIConstants.au3>
#include <WindowsConstants.au3>
;

Global Const $WH_CALLWNDPROC = 4

$hWnd = WinGetHandle("[CLASS:OpWindow]")
$ThreadID = WinGetProcess($hWnd)

$Callback = DllCallbackRegister("_CallWndProc", "long", "int;wparam;lparam")
$HHOOK = DllCall("User32.dll", "hwnd", "SetWindowsHookEx", "int", $WH_CALLWNDPROC, _
        "ptr", DllCallbackGetPtr($Callback), "hwnd", 0, "dword", $ThreadID)

Sleep(5000)

Func _CallWndProc($nCode, $wParam, $lParam)
    If $nCode < 0 Then
        Local $a_Ret = DllCall("user32.dll", "long", "CallNextHookEx", _
                "hwnd", $HHOOK[0], "int", $nCode, "wparam", $wParam, "lparam", $lParam)
        
        Return $a_Ret[0]
    EndIf
    
    Local $CWPSTRUCT = DllStructCreate("long lParam;long wParam;uint Message;hwnd hWnd", $lParam)
    If @error Then Exit
    
    If DllStructGetData($CWPSTRUCT, "Message") = $WM_CLOSE Then
        ConsoleWrite("Here i need to minimize (or other operations) the window..." & @CRLF)
        ;Send("^h")
        Return 1
    EndIf
    
    $CWPSTRUCT = 0
EndFunc

Func OnAutoItExit()
    DllCall("user32.dll", "hwnd", "UnhookWindowsHookEx", "hwnd", $HHOOK[0])
    DllCallbackFree($Callback)
EndFunc

But the problem here is that the _CallWndProc even not registered, and not called. The same hook working well (taken from here) on AutoIt's GUI (the function _CallWndProc called anyway), but not on external window. What is wrong here?

[exodius]

Is this intended to work differently than just specifying that you want the window to minimize instead of exit for $GUI_EVENT_CLOSE?

[MrCreatoR]

Is this intended to work differently than just specifying that you want the window to minimize instead of exit for $GUI_EVENT_CLOSE?

I am not sure that i understand, $GUI_EVENT_CLOSE is for autoit's GUI, and i need it for external window.

[FreeFry]

From what I remember, any hooks(except keyboard and mouse ones), require the callback procedure to be located inside a dll.. So you'd need a custom crafted dll to do what you want. :/