TopMost problems

[E Goforth]

Hello,

I have a VB6 app that calls a VB.NET app via named pipes and a third
party component. Inside the VB.NET app I'm trying to force a form to
the top, at least temporarily. Inside a form's public sub I'm doing:

Public Sub ThisIsMySub(The seAreMyArgument s)
Me.Show
Me.WindowState = FormWindowState .Normal
Me.TopMost = True
Me.TopMost = False
End Sub

However, my form doesn't pop on top like I'd expect it to. BTW the form
is an MDIParent.

I wrote a simple proof-of-concept VB.NET application with a timer
control on an MDI Parent form. I do the same steps as above it works as
I'd expect. When the timer_tick event fires my MDIParent form pops on
top. I can then move another app on top of it or minimize my MDIParent
form. The next time the timer_tick event fires it pops back on top.

The only thing that I could figure out is that another form in my app
had it's TopMost property set to True. I have a StatusBar form that
does this, but I did some checking and its unloaded by the time I do my
"Me.TopMost = True
" Any idea what could be going on?

Thanks,
Eric
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[Tom Shelton]

In article <OD************ **@TK2MSFTNGP11 .phx.gbl>, E Goforth wrote:

Hello,

Do the AllowSetForegro undWindow and SetForegroundWi ndow APIs make the
window in the foreground permanently? I just want it to pop to the top
of the z-order, but then allow the user to put other windows on top, if
they want to.

Eric Goforth
Raleigh, NC

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No they don't make them on top permanently. All they do is let you
steal the focus. Of course, using the
AllowSetForegro undWindow/SetForegroundWi ndow - you are setting it up so
that your second app can steal focus from your first, but it still will
not be able to steal focus from any other app. To make it universal,
you have to use the AttachThreadInp ut method...

I think though that you have another issue going on. Can you remind me
of how your doing the communication - was it with pipes?

--
Tom Shelton
MVP [Visual Basic]

[E Goforth]

Hello,

I added the following declarations to my MDIParent form:

---- Begin code ------------------

Private Declare Function GetTopWindow Lib "user32.dll " (ByVal hWnd
As IntPtr) As IntPtr
Private Declare Function SetForegroundWi ndow Lib "user32" (ByVal
hwnd As IntPtr) As IntPtr
Private Declare Function GetWindowText Lib "user32" Alias
"GetWindowTextA " (ByVal hwnd As IntPtr, ByVal lpString As String, ByVal
cch As Long) As Long
Private Declare Function SetWindowPos Lib "user32" Alias
"SetWindowP os" (ByVal hwnd As IntPtr, ByVal hWndInsertAfter As Long,
ByVal x As Long, ByVal y As Long, ByVal cx As Long, ByVal cy As Long,
ByVal wFlags As Long) As Long

Private Const HWND_TOP As Integer = 0
Private Const HWND_BOTTOM As Integer = 1
Private Const HWND_TOPMOST As Integer = -1
Private Const HWND_NOTOPMOST As Integer = -2
Private Const SWP_NOSIZE As Long = &H1
Private Const SWP_NOMOVE As Long = &H2

Inside my public sub I have:

Me.Show()
Me.WindowState = FormWindowState .Normal

Trace("frmMain. LoadMyForm", "++++++++++++++ +++++++++++ (2) - Me.Handle =
" & Me.Handle.ToStr ing & ", TopWindow = " &
GetTopWindow(Me .Handle).ToStri ng)

'Me.TopMost = True
Dim strTest As String
GetWindowText(G etTopWindow(Me. Handle), strTest, 100)

Trace("frmMain. LoadMyForm", "(2) Prior to doing the SetForegroundWi ndow,
TopWindow Name = " & strTest)

'SetForegroundW indow(Me.Handle )
SetWindowPos(Me .Handle, HWND_TOPMOST, Me.Left, Me.Top, Me.Width,
Me.Height, SWP_NOMOVE Or SWP_NOSIZE)

Trace("frmMain. LoadMyForm", "(2) After doing the SetForegroundWi ndow
Me.Handle = " & Me.Handle.ToStr ing & ", TopWindow = " &
GetTopWindow(Me .Handle).ToStri ng)

Trace("frmMain. LoadMyForm", "(2) - Me.TopMost = " & Me.TopMost.ToSt ring)
Trace("frmMain. LoadMyForm", "(2) - Me.Visible = " & Me.Visible.ToSt ring)
Trace("frmMain. LoadMyForm", "(2) - Me.WindowState = " &
Me.WindowState. ToString)
Trace("frmMain. LoadMyForm", "(2) - Me.Position = " & Me.Left.ToStrin g &
", " & Me.Top.ToString )

'Me.TopMost = False
SetWindowPos(Me .Handle, HWND_NOTOPMOST, Me.Left, Me.Top, Me.Width,
Me.Height, SWP_NOMOVE Or SWP_NOSIZE)

Trace("frmMain. LoadMyForm", "(3) - Me.TopMost = " & Me.TopMost.ToSt ring)

---- End code ------------------

It shrinks my window and puts it all the way in the upper left hand
corner of the screen. I thought that the coordinates system in .NET and
Windows was different, but would have expected the "SWP_NOMOVE Or
SWP_NOSIZE" to prevent that.

Other than that, it works the same as doing the Me.TopMost = True
shortly followed by a Me.TopMost = False. My form doesn't pop to the
top of the z-order that I can see.

My tracefile shows:

10/16/2003 1:46:59 PM : frmMain.LoadMyF orm :
+++++++++++++++ ++++++++++ (2) - Me.Handle = 8390128, TopWindow
= 11142560
10/16/2003 1:46:59 PM : frmMain.LoadMyF orm :
(2) Prior to doing the SetForegroundWi ndow, TopWindow Name =
10/16/2003 1:46:59 PM : frmMain.LoadMyF orm :
(2) After doing the SetForegroundWi ndow Me.Handle = 8390128,
TopWindow = 11142560
10/16/2003 1:46:59 PM : frmMain.LoadMyF orm :
(2) - Me.TopMost = False
10/16/2003 1:46:59 PM : frmMain.LoadMyF orm :
(2) - Me.Visible = True
10/16/2003 1:46:59 PM : frmMain.LoadMyF orm :
(2) - Me.WindowState = Normal
10/16/2003 1:46:59 PM : frmMain.LoadMyF orm :
(2) - Me.Position = -1, 103
10/16/2003 1:46:59 PM : frmMain.LoadMyF orm :
(3) - Me.TopMost = False
10/16/2003 1:46:59 PM : frmMain.LoadMyF orm :
Exit routine
Eric Goforth
Raleigh, NC

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[Tom Shelton]

In article <O$************ **@TK2MSFTNGP11 .phx.gbl>, E Goforth wrote:

Hello,

I added the following declarations to my MDIParent form:

---- Begin code ------------------

<snip>
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Some of your declares are wrong... Any way, here is an example of using
SetForegroundWi ndow...

Option Strict On
Option Explicit On

Public Class Form1
Inherits System.Windows. Forms.Form

#Region " Windows Form Designer generated code "

Public Sub New()
MyBase.New()

'This call is required by the Windows Form Designer.
InitializeCompo nent()

'Add any initialization after the InitializeCompo nent() call

End Sub

'Form overrides dispose to clean up the component list.
Protected Overloads Overrides Sub Dispose(ByVal disposing As
Boolean)
If disposing Then
If Not (components Is Nothing) Then
components.Disp ose()
End If
End If
MyBase.Dispose( disposing)
End Sub

'Required by the Windows Form Designer
Private components As System.Componen tModel.IContain er

'NOTE: The following procedure is required by the Windows Form
Designer
'It can be modified using the Windows Form Designer.
'Do not modify it using the code editor.
Friend WithEvents Timer1 As System.Windows. Forms.Timer
<System.Diagnos tics.DebuggerSt epThrough()> Private Sub
InitializeCompo nent()
Me.components = New System.Componen tModel.Containe r
Me.Timer1 = New System.Windows. Forms.Timer(Me. components)
'
'Timer1
'
Me.Timer1.Enabl ed = True
Me.Timer1.Inter val = 10000
'
'Form1
'
Me.AutoScaleBas eSize = New System.Drawing. Size(5, 13)
Me.ClientSize = New System.Drawing. Size(608, 453)
Me.IsMdiContain er = True
Me.Name = "Form1"
Me.Text = "Form1"

End Sub

#End Region

Private Declare Function GetCurrentThrea dId Lib "kernel32" () As
IntPtr

Private Declare Function AttachThreadInp ut Lib "user32" _
(ByVal idAttach As IntPtr, _
ByVal idAttachTo As IntPtr, _
ByVal fAttach As Boolean) As Boolean

Private Declare Function GetWindowThread ProcessId Lib "user32" _
(ByVal hWnd As IntPtr, _
ByVal lpdwProcessId As IntPtr) As IntPtr

Private Declare Function SetForegroundWi ndow Lib "user32" (ByVal
hWnd As IntPtr) As Boolean
Private Declare Function GetForegroundWi ndow Lib "user32" () As
IntPtr

Private Sub Timer1_Tick(ByV al sender As System.Object, ByVal e As
System.EventArg s) Handles Timer1.Tick
If Me.WindowState = FormWindowState .Minimized Then
Me.WindowState = FormWindowState .Normal
End If

Dim foregroundThrea d As IntPtr =
GetWindowThread ProcessId(GetFo regroundWindow( ), IntPtr.Zero)
Dim currentThread As IntPtr = GetCurrentThrea dId()

If Not foregroundThrea d.Equals(curren tThread) Then
AttachThreadInp ut(foregroundTh read, currentThread, True)
End If

SetForegroundWi ndow(Me.Handle)

If Not foregroundThrea d.Equals(curren tThread) Then
AttachThreadInp ut(foregroundTh read, currentThread, False)
End If

End Sub

Private Sub Form1_Load(ByVa l sender As System.Object, ByVal e As
System.EventArg s) Handles MyBase.Load
Dim f As New Form2
f.MdiParent = Me
f.Visible = True
End Sub
End Class

HTH
--
Tom Shelton
MVP [Visual Basic]