Prevent users from terminating an application???

[subhendu]

Hi guys,

I have an application which runs on server, which I do not want to be terminated (using ctrl+alt+del) by the users.

Since the application generates report and also works as query pad, I don't not want to hide the application using 'RegisterServiceProcess'!!!

I have seen applications where when the users try to terminate an application they are asked for password and only then they are allowed to shut down the application.

How do I achieve this???

Thanks
Subhendu.

[Hack]

Private Sub Form_QueryUnload(Cancel As Integer, UnloadMode As Integer)
'enter code for password here.   if password is valid, allow the shutdown
'if password is invalid, issue a Cancel = -1 to terminate the shutdown
End Sub

[subhendu]

Hi Hack,

Thanks for your suggestion.

But, I still have problem areas!!!

The moment I ask the user to enter the password, the windows shows that the application has stopped responding and asks the user to 'End Task', 'Wait', 'Cancel' the process.

Plus, I find usually by Ctrl+Alt+Del many times allows the application to be terminated!!!

I DO need more help !!!

Thanks.

[zanalkhan]

Why don't you restrict user from using the (ctl +alt+del) all the way !.
Use,
SystemParametersInfo API,and use its serv. No (97) to restrict termination Window from Windows

[baja_yu]

Hi,

this is an old thread but I have a similar need.
Is there a way to prevent it from being terminated, not only by users (ctrl+alt+delete) but by other apps too?

I am trying to build a security application which I dont want being terminated by malicious applications like trojans and viruses.

[Dayhawk]

Try hidding it from the application list.

[baja_yu]

Yes, but I think it still does get listed as a process and it can be found there and terminated.

[Jlarini]

Hi, guys!!!

I had a problem sometime ago, where I need to catch when the user tries to close an app. So I used this...

I Hope it can help....

Declare Function CallWindowProc Lib "user32" Alias "CallWindowProcA" _
    (ByVal lpPrevWndFunc As Long, ByVal hwnd As Long, ByVal MSG As Long, _
    ByVal wParam As Long, ByVal lParam As Long) As Long
    
Declare Function SetWindowLong Lib "user32" Alias "SetWindowLongA" _
    (ByVal hwnd As Long, ByVal nIndex As Long, ByVal dwNewLong As Long) As Long
    
Declare Function GetMessage Lib "user32" Alias "GetMessageA" _
    (lpMsg As MSG, ByVal hwnd As Long, ByVal wMsgFilterMin As Long, _
    ByVal wMsgFilterMax As Long) As Long
    
    
Type POINTAPI
    X As Long
    y As Long
End Type
 
Type MSG
    hwnd    As Long
    message As Long
    wParam  As Long
    lParam  As Long
    time    As Long
    pt      As POINTAPI
End Type
 
Public Const GWL_WNDPROC = -4
Public Const WM_QUERYENDSESSION = &H11
Public Const WM_CANCELMODE = &H1F
 
Public SDAttempt        As Long
Global lpPrevWndProc    As Long
Global gHW              As Long
 
Dim sSql    As String
 
'Holds on
Public Sub Hook()
    lpPrevWndProc = SetWindowLong(gHW, GWL_WNDPROC, AddressOf WindowProc)
End Sub
 
'Lets close
Public Sub Unhook()
    Dim temp    As Long
    temp = SetWindowLong(gHW, GWL_WNDPROC, lpPrevWndProc)
End Sub
 
Function WindowProc(ByVal hw As Long, ByVal uMsg As Long, _
    ByVal wParam As Long, ByVal lParam As Long) As Long
    
    Dim a As Long
    
    If uMsg = WM_QUERYENDSESSION Then
        'your code here 
        hook
    End If
    WindowProc = CallWindowProc(lpPrevWndProc, hw, uMsg, wParam, lParam)
    
End Function

JL

[baja_yu]

How is this code used?

[Jlarini]

baja,

When I used this code, I had problems because, some users just shuts down (using Start, shutdown) without close my app, and as I control who's using it, I need that when it closes that, the app saves it in a table... (such as an Yes/No field)...


The hook, activate an "catch" that controls if the app is been closed and then made something you want, and then you need to unhook to let it close... (I used it sometime ago, so I don't remember exactly how it acts, but its something like that...)


I'll take a look on my app, so I can answer more correctly. OK ?

edit: Yes, as I said before it works that way...

When you start your app, you need to Hook when you start your app, and to close the app you need to Unhook on MDIForm_Unload / Form_Unload.

One possible problem... If you're in debuggin, comment Hook's line, cos, often, it crashes VB.... It's a pain ass, but... It works fine...



JL

[baja_yu]

Ok. Thanks.

[baja_yu]

Ok. Thanks.