Suspend system until user response

[philv]

Hi,

Fairly new to VB...

I have a single form application that is executed via an NT login script when a user logs in. The form (always on top) shows our rules and regulations for our systems and asks the user to accept or decline them (similar to a software license agreement). If they decline they are logged out - if they accept it is recorded and they can continue.

However, they can bypass in various ways such as clicking the login script cmd window behind the form and manually stopping the login script, or killing the VB app from task manager.

Is there a way to suspend the rest of the system while this form is displayed until a user has pressed 'Accept' or 'Decline'? i.e. the user can do nothing (maybe not even task manager???) until they have hit one of the two buttons.

Many thanks,

PhilVee

[HeSaidJoe]

This might work.

display your form as vbModal/Topmost/ and disable
the alt/tab/delete
don't forget to re-enable it after admission

'this code will disable  [Alt-Tab ] or [ Ctrl-Alt-Del ]
'
'build a bas module and put this in it.
'
Private Declare Function EnableWindow Lib "user32" (ByVal hWnd As Integer, ByVal aBOOL As Integer) As Integer
Private Declare Function IsWindowEnabled Lib "user32" (ByVal hWnd As Integer) As Integer

Private Declare Function GetMenu Lib "user32" (ByVal hWnd As Integer) As Integer

Private Declare Function FindWindow Lib "user32" Alias "FindWindowA" (ByVal lpClassName As String, ByVal lpWindowName As String) As Long

Private Declare Function SystemParametersInfo Lib "user32" Alias "SystemParametersInfoA" (ByVal uAction As Long, ByVal uParam As Long, ByVal lpvParam As Any, ByVal fuWinIni As Long) As Long

Private TaskBarhWnd As Long
Private IsTaskBarEnabled As Integer
Private TaskBarMenuHwnd As Integer

Sub FastTaskSwitching(bEnabled As Boolean)

Dim X As Long, bDisabled As Long

    bDisabled = Not bEnabled

    X = SystemParametersInfo(97, bDisabled, CStr(1), 0)

End Sub

Public Sub DisableTaskBar()

Dim EWindow As Integer

    TaskBarhWnd = FindWindow("Shell_traywnd", "")

    If TaskBarhWnd <> 0 Then

        'check to see if window is enabled

        EWindow = IsWindowEnabled(TaskBarhWnd)

        If EWindow = 1 Then 'need to disable it

            IsTaskBarEnabled = EnableWindow(TaskBarhWnd, 0)

        End If

    End If

End Sub

 

Public Sub EnableTaskBar()

    If IsTaskBarEnabled = 0 Then

        IsTaskBarEnabled = EnableWindow(TaskBarhWnd, 1)

    End If

End Sub
'
'
' put 2 option buttons on your form
' option 1 = enable ....option 2 = disable
' code for click event of option buttons

Private Sub Option1_Click()

	EnableTaskBar
	FastTaskSwitching True

End Sub

Private Sub Option2_Click()

	DisableTaskBar
	FastTaskSwitching False

End Sub

[HeSaidJoe]

Just in case you are in doubt as to
showing your form as vbModal
set your project properties to start
up Sub Main and not your form.

[code]
'create a bas module and put this in it
'use your form name in place of Form1

Sub Main()
Form1.Show (vbModal)
End Sub
[code}

[philv]

Many thanks for that - I'll give it a go...

[philv]

Getting an overflow error on the line:

EWindow = IsWindowEnabled(TaskBarhWnd)

Any thoughts, or could I be doing this wrong. Put the code in a bas module - then to try put 2 buttons on the form with the given click code.

you could use a SystemModal Message box with a yes and a no button...

Private Sub Command1_Click()

    MsgBox "do you accept?", vbYesNo + vbCritical + vbSystemModal

End Sub

[HeSaidJoe]

I don't know why...did you copy and paste the code
or type it in...
I copied and pasted the code and it works fine on my system
Changed the form name, etc without problems.

the code for the option buttons or command buttons
goes in your form not the module.

[philv]

Copy and pasted, and then put the button code in the form. Can't quite work it out. Using VB5 - could that be a problem?

[HeSaidJoe]

I guess it could be possible but I can't test the theory as all I have is VB6.

Is it still the same error. and can you cut and paste your module code and your form code so I can run it?

[philv]

Yep, same error.

I've created a very basic app to try this out, i.e. a form and two buttons. Below is the code i have put into the form:

Private Sub Command1_Click()

    MsgBox "do you accept?", vbYesNo + vbCritical + vbSystemModal


End Sub

Private Sub Command2_Click()

    DisableTaskBar
    FastTaskSwitching False

End Sub

The following is in another module to start the form in modal:

Sub Main()
    Form1.Show (vbModal)
End Sub

The following code is in another module, and is simple copied and pasted from your code:

'this code will disable  [Alt-Tab ] or [ Ctrl-Alt-Del ]
'
'build a bas module and put this in it.
'
Private Declare Function EnableWindow Lib "user32" (ByVal hWnd As Integer, ByVal aBOOL As Integer) As Integer
Private Declare Function IsWindowEnabled Lib "user32" (ByVal hWnd As Integer) As Integer

Private Declare Function GetMenu Lib "user32" (ByVal hWnd As Integer) As Integer

Private Declare Function FindWindow Lib "user32" Alias "FindWindowA" (ByVal lpClassName As String, ByVal lpWindowName As String) As Long

Private Declare Function SystemParametersInfo Lib "user32" Alias "SystemParametersInfoA" (ByVal uAction As Long, ByVal uParam As Long, ByVal lpvParam As Any, ByVal fuWinIni As Long) As Long

Private TaskBarhWnd As Long
Private IsTaskBarEnabled As Integer
Private TaskBarMenuHwnd As Integer

Sub FastTaskSwitching(bEnabled As Boolean)

Dim X As Long, bDisabled As Long

    bDisabled = Not bEnabled

    X = SystemParametersInfo(97, bDisabled, CStr(1), 0)

End Sub

Public Sub DisableTaskBar()

Dim EWindow As Integer

    TaskBarhWnd = FindWindow("Shell_traywnd", "")

    If TaskBarhWnd <> 0 Then

        'check to see if window is enabled

        EWindow = IsWindowEnabled(TaskBarhWnd)

        If EWindow = 1 Then 'need to disable it

            IsTaskBarEnabled = EnableWindow(TaskBarhWnd, 0)

        End If

    End If

End Sub

 

Public Sub EnableTaskBar()

    If IsTaskBarEnabled = 0 Then

        IsTaskBarEnabled = EnableWindow(TaskBarhWnd, 1)

    End If

End Sub

Once again many thanks for this - please bear with me as I'm only a beginner!

[philv]

Code for form was wrong - that was when I was trying out the system modal message box. Below is the form code:

Private Sub Option1_Click()

	EnableTaskBar
	FastTaskSwitching True

End Sub

Private Sub Option2_Click()

	DisableTaskBar
	FastTaskSwitching False

End Sub

Cheers,

[HeSaidJoe]

Sorry it took a little, I'm at work.
Ok..I have removed subMain so now all you need do to
test this out is start a new app.(standard)
Add a module and paste the module code into it.
Call your form frmMain and then paste the code for
frmMain into it
Add a form and call it frmInside and post the code
for it inside it.

This does exactly as you want and works..tested!
If it gives you problems then it must be because
you can't use the alt/ctrl/delete functions in vb5
That might be your new question...how to kill alt/ctrl delete in vb5

'<<<<<<<<<<<this is the bas module code>>>>>>>>>>>>>

Option Explicit

'disable the alt tab delete functions..no way to get to task list

Public Declare Function EnableWindow Lib _
"user32" (ByVal hWnd As Integer, ByVal aBOOL As Integer) _
As Integer

Public Declare Function IsWindowEnabled Lib _
"user32" (ByVal hWnd As Integer) As Integer

Public Declare Function GetMenu Lib "user32" _
(ByVal hWnd As Integer) As Integer

Public Declare Function FindWindow Lib "user32" _
Alias "FindWindowA" (ByVal lpClassName As String, _
ByVal lpWindowName As String) As Long

Public Declare Function SystemParametersInfo Lib _
"user32" Alias "SystemParametersInfoA" _
(ByVal uAction As Long, ByVal uParam As Long, _
ByVal lpvParam As Any, ByVal fuWinIni As Long) As Long

Public TaskBarhWnd As Long
Public IsTaskBarEnabled As Integer
Public TaskBarMenuHwnd As Integer

Sub FastTaskSwitching(bEnabled As Boolean)

    Dim X As Long, bDisabled As Long

    bDisabled = Not bEnabled

    X = SystemParametersInfo(97, bDisabled, CStr(1), 0)

End Sub

Public Sub DisableTaskBar()

    Dim EWindow As Integer

    TaskBarhWnd = FindWindow("Shell_traywnd", "")

    If TaskBarhWnd <> 0 Then

        'check to see if window is enabled

        EWindow = IsWindowEnabled(TaskBarhWnd)

        If EWindow = 1 Then 'need to disable it

            IsTaskBarEnabled = EnableWindow(TaskBarhWnd, 0)

        End If

    End If

End Sub


Public Sub EnableTaskBar()

    If IsTaskBarEnabled = 0 Then

        IsTaskBarEnabled = EnableWindow(TaskBarhWnd, 1)

    End If

End Sub

Public Sub UnloadForms()
  'enable the alt/ctrl/del functions
      EnableTaskBar
      FastTaskSwitching True
  Dim Form As Form
       For Each Form In Forms
         Unload Form
           Set Form = Nothing
       Next Form
End Sub

'<<<<<<<<< this is frmMain code >>>>>>>>>>>>
'this form controls the alt/ctrl/delete and exit routines

'This code goes in frmMain
'frmMain is set to invisible in form active and is
'never shown

Option Explicit

Private Sub Form_Activate()

frmmain.Visible = False

Dim sResult As Single

'kill alt/ctrl/delete functions
    DisableTaskBar
    FastTaskSwitching False
    sResult = MsgBox("Do you accept?", vbYesNo, "Entrance Exam")
 
'if accepted then enable and go onward
If sResult = 6 Then
    EnableTaskBar
      FastTaskSwitching True
        frmInside.Show
Else
'else quit
    Call UnloadForms
End If

End Sub

'<<<<<<<<<<<<<<<  this is frmInside code >>>>>>>>>>>>>>>>
'this is your form once you get past the yes/no

Option Explicit


Private Sub Command1_Click()
    Call UnloadForms
End Sub

Private Sub Form_Activate()

End Sub

[Edited by HeSaidJoe on 08-17-2000 at 11:00 AM]

[philv]

Many thanks for all your time on this - I'll be trying it out tomorrow (finish work soon). If indeed it does not work then we know it's a VB5 issue, and I'll look to upgrade to VB6.
Thanks again - I will post just to let you know the result