"Clemente" <clemente.fil***@gmail.com> wrote in message
news:3f47b67e-88ba-4d67-9bd0-3f9885c0d3d3@x69g2000hsx.googlegroups.com...
> Hi,
>
> We have a VB.Net application that is sleeping until it receives a
> logoff/shutdown event. We want the application running on Vista and
> XP.
>
> When the application receives those events it has to show a message
> box, so the user can answer Yes or No, and then let the logoff/
> shutdown process continues.
>
> We are doing this in VB.Net listening to WM_QUERYENDSESSION message.
>
> We are having the following problems:
>
> . - It doesnt work in Vista.
>  - In XP, when the application receives the WM_QUERYENDSESSION
> message it shows the System End Task window for this application,
> before showing the message box we want.
>
> We are using this VB . Net code:
>
> ---------------------------
>    Private Shared WM_QUERYENDSESSION As Integer = &H11
>    Private Shared systemShutdown As Boolean = False
>
>    Protected Overrides Sub WndProc(ByRef m As
> System.Windows.Forms.Message)
>        If m.Msg = WM_QUERYENDSESSION Then
>            'MessageBox.Show("queryendsession: this is a logoff,
> shutdown, or reboot")
>            systemShutdown = True
>        End If
>        ' If this is WM_QUERYENDSESSION, the closing event should be
> raised in the base WndProc.
>        MyBase.WndProc(m)
>    End Sub 'WndProc
> -------------------------
>    Private Sub frmMsg_FormClosing(ByVal sender As Object, ByVal e As
> System.Windows.Forms.FormClosingEventArgs) Handles Me.FormClosing
>        If (systemShutdown) Then
>            ' Reset the variable because the user might cancel the
> shutdown.
>            systemShutdown = False
>            If (System.Windows.Forms.DialogResult.Yes =
> MessageBox.Show("My application", "Abort logoff?",
> MessageBoxButtons.YesNo)) Then
>                e.Cancel = True
>            Else
>                e.Cancel = False
>            End If
>        End If
>    End Sub
> -----------------------
>
> Why this behaviour? Any ideas?
>
> TIA,
>
> Clemente
> Portugal