Window handle for a MessageBox

[Leonardo Bosi]

Hello,

From my VB app, I have to show a message box (using the MsgBox native VB
function, or one of the MessageBox API functions), and be able to remove the
message box from my code when a Timer event occurs (if the user didn't close
it until that moment). To achieve this, I thought I could get the handle to
the message box window, in order to close that window (using either
CloseWindow or DestroyWindow). So I'm asking: Is there a way for me to get
the window handle for a message box I showed from my code? I read the
documentation for the different API functions used to create message boxes
(MessageBox, MessageBoxEx, MessageBoxIndirect), and didn't find in any of
them a way for me to get that window handle...

Any help would be appreciated...

Thanks,


Leonardo Bosi
Proximity Soft
Buenos Aires, Argentina
--------------------------------------------
leobosi@proximity.com.ar
http://www.proximity.com.ar

[Jonathan Wood]

I don't think you can do this for the simple reason that VB code does not
run while a message box is displayed.

Moreover, if it did, this seems like a lot of hassle. I would definitely
just create a custom form for your message box and implement your timer in
the code for that form.

--
Jonathan Wood
SoftCircuits Programming
http://www.softcircuits.com

Leonardo Bosi <leobosi@proximity.com.ar> wrote in message
news:3915eebe@news.devx.com...
> Hello,
>
> From my VB app, I have to show a message box (using the MsgBox native VB
> function, or one of the MessageBox API functions), and be able to remove
the
> message box from my code when a Timer event occurs (if the user didn't
close
> it until that moment). To achieve this, I thought I could get the handle
to
> the message box window, in order to close that window (using either
> CloseWindow or DestroyWindow). So I'm asking: Is there a way for me to get
> the window handle for a message box I showed from my code? I read the
> documentation for the different API functions used to create message boxes
> (MessageBox, MessageBoxEx, MessageBoxIndirect), and didn't find in any of
> them a way for me to get that window handle...
>
> Any help would be appreciated...
>
> Thanks,
>
>
> Leonardo Bosi
> Proximity Soft
> Buenos Aires, Argentina
> --------------------------------------------
> leobosi@proximity.com.ar
> http://www.proximity.com.ar
>
>

[Jonathan Wood]

I don't think you can do this for the simple reason that VB code does not
run while a message box is displayed.

Moreover, if it did, this seems like a lot of hassle. I would definitely
just create a custom form for your message box and implement your timer in
the code for that form.

--
Jonathan Wood
SoftCircuits Programming
http://www.softcircuits.com

Leonardo Bosi <leobosi@proximity.com.ar> wrote in message
news:3915eebe@news.devx.com...
> Hello,
>
> From my VB app, I have to show a message box (using the MsgBox native VB
> function, or one of the MessageBox API functions), and be able to remove
the
> message box from my code when a Timer event occurs (if the user didn't
close
> it until that moment). To achieve this, I thought I could get the handle
to
> the message box window, in order to close that window (using either
> CloseWindow or DestroyWindow). So I'm asking: Is there a way for me to get
> the window handle for a message box I showed from my code? I read the
> documentation for the different API functions used to create message boxes
> (MessageBox, MessageBoxEx, MessageBoxIndirect), and didn't find in any of
> them a way for me to get that window handle...
>
> Any help would be appreciated...
>
> Thanks,
>
>
> Leonardo Bosi
> Proximity Soft
> Buenos Aires, Argentina
> --------------------------------------------
> leobosi@proximity.com.ar
> http://www.proximity.com.ar
>
>

[Sixto Santos]

Hello Jonathan!

Although it is true that an application would stop execution while a MsgBox
is being displayed, a Timer control would still execute the Timer event but
only at run-time, so you must compile and run the application to take
advantage of it.

Knowing this we can use the FindWindow and the SendMessage API functions to
find and close the message box.

To test it, add a Command button and a Timer to a form, add the code bellow
and compile and run the program. The message box would close one second
after being displayed.

' CODE BEGINS ----------------------
Private Declare Function FindWindow Lib "user32" Alias "FindWindowA" _
(ByVal lpClassName As String, ByVal lpWindowName As String) As Long
Private Declare Function SendMessage Lib "user32" Alias "SendMessageA" _
(ByVal hwnd As Long, ByVal wMsg As Long, ByVal wParam As Long, lParam As
Long) As Long
Private Const WM_CLOSE = &H10

Private Sub Command1_Click()
Timer1.Interval = 1000
Timer1.Enabled = True
MsgBox "Close Me", vbExclamation, "MsgBox Caption"

End Sub

Private Sub Timer1_Timer()
Dim hwnd As Long

hwnd = FindWindow("#32770", "MsgBox Caption")
If hwnd > 0 Then
Call SendMessage(hwnd, WM_CLOSE, 0, 0)
End If

End Sub

' CODE ENDS ----------------------

On the other hand, I would definitely go with your suggestion and create a
custom message box with a timer.


Regards,

Sixto



Jonathan Wood <jwood@softcircuits.com> wrote in message
news:3916034e$1@news.devx.com...
> I don't think you can do this for the simple reason that VB code does not
> run while a message box is displayed.
>
> Moreover, if it did, this seems like a lot of hassle. I would definitely
> just create a custom form for your message box and implement your timer in
> the code for that form.
>
> --
> Jonathan Wood
> SoftCircuits Programming
> http://www.softcircuits.com
>
> Leonardo Bosi <leobosi@proximity.com.ar> wrote in message
> news:3915eebe@news.devx.com...
> > Hello,
> >
> > From my VB app, I have to show a message box (using the MsgBox native VB
> > function, or one of the MessageBox API functions), and be able to remove
> the
> > message box from my code when a Timer event occurs (if the user didn't
> close
> > it until that moment). To achieve this, I thought I could get the handle
> to
> > the message box window, in order to close that window (using either
> > CloseWindow or DestroyWindow). So I'm asking: Is there a way for me to
get
> > the window handle for a message box I showed from my code? I read the
> > documentation for the different API functions used to create message
boxes
> > (MessageBox, MessageBoxEx, MessageBoxIndirect), and didn't find in any
of
> > them a way for me to get that window handle...
> >
> > Any help would be appreciated...
> >
> > Thanks,
> >
> >
> > Leonardo Bosi
> > Proximity Soft
> > Buenos Aires, Argentina
> > --------------------------------------------
> > leobosi@proximity.com.ar
> > http://www.proximity.com.ar
> >
> >
>
>

[Sixto Santos]

Hello Jonathan!

Although it is true that an application would stop execution while a MsgBox
is being displayed, a Timer control would still execute the Timer event but
only at run-time, so you must compile and run the application to take
advantage of it.

Knowing this we can use the FindWindow and the SendMessage API functions to
find and close the message box.

To test it, add a Command button and a Timer to a form, add the code bellow
and compile and run the program. The message box would close one second
after being displayed.

' CODE BEGINS ----------------------
Private Declare Function FindWindow Lib "user32" Alias "FindWindowA" _
(ByVal lpClassName As String, ByVal lpWindowName As String) As Long
Private Declare Function SendMessage Lib "user32" Alias "SendMessageA" _
(ByVal hwnd As Long, ByVal wMsg As Long, ByVal wParam As Long, lParam As
Long) As Long
Private Const WM_CLOSE = &H10

Private Sub Command1_Click()
Timer1.Interval = 1000
Timer1.Enabled = True
MsgBox "Close Me", vbExclamation, "MsgBox Caption"

End Sub

Private Sub Timer1_Timer()
Dim hwnd As Long

hwnd = FindWindow("#32770", "MsgBox Caption")
If hwnd > 0 Then
Call SendMessage(hwnd, WM_CLOSE, 0, 0)
End If

End Sub

' CODE ENDS ----------------------

On the other hand, I would definitely go with your suggestion and create a
custom message box with a timer.


Regards,

Sixto



Jonathan Wood <jwood@softcircuits.com> wrote in message
news:3916034e$1@news.devx.com...
> I don't think you can do this for the simple reason that VB code does not
> run while a message box is displayed.
>
> Moreover, if it did, this seems like a lot of hassle. I would definitely
> just create a custom form for your message box and implement your timer in
> the code for that form.
>
> --
> Jonathan Wood
> SoftCircuits Programming
> http://www.softcircuits.com
>
> Leonardo Bosi <leobosi@proximity.com.ar> wrote in message
> news:3915eebe@news.devx.com...
> > Hello,
> >
> > From my VB app, I have to show a message box (using the MsgBox native VB
> > function, or one of the MessageBox API functions), and be able to remove
> the
> > message box from my code when a Timer event occurs (if the user didn't
> close
> > it until that moment). To achieve this, I thought I could get the handle
> to
> > the message box window, in order to close that window (using either
> > CloseWindow or DestroyWindow). So I'm asking: Is there a way for me to
get
> > the window handle for a message box I showed from my code? I read the
> > documentation for the different API functions used to create message
boxes
> > (MessageBox, MessageBoxEx, MessageBoxIndirect), and didn't find in any
of
> > them a way for me to get that window handle...
> >
> > Any help would be appreciated...
> >
> > Thanks,
> >
> >
> > Leonardo Bosi
> > Proximity Soft
> > Buenos Aires, Argentina
> > --------------------------------------------
> > leobosi@proximity.com.ar
> > http://www.proximity.com.ar
> >
> >
>
>

[Leonardo Bosi]

Hello Jonathan,

You're right, when using the native VB elements (Timer control and the
MsgBox function) for this task, the VB code doesn't continue executing until
the user closes the MsgBox, and timer events don't fire. But if the
application is compiled as an executable, it does (see Sixto's message in
this thread). Additionally, if we use the MessageBox API function instead of
the MsgBox VB native function, it also works while in the VB IDE.

Thanks!


Leonardo Bosi
Proximity Soft
Buenos Aires, Argentina
--------------------------------------------
leobosi@proximity.com.ar
http://www.proximity.com.ar

[Leonardo Bosi]

Hello Jonathan,

You're right, when using the native VB elements (Timer control and the
MsgBox function) for this task, the VB code doesn't continue executing until
the user closes the MsgBox, and timer events don't fire. But if the
application is compiled as an executable, it does (see Sixto's message in
this thread). Additionally, if we use the MessageBox API function instead of
the MsgBox VB native function, it also works while in the VB IDE.

Thanks!


Leonardo Bosi
Proximity Soft
Buenos Aires, Argentina
--------------------------------------------
leobosi@proximity.com.ar
http://www.proximity.com.ar

[Leonardo Bosi]

Hello Sixto,

Thanks for your help, I solved my problem using that code. Note that I used
the MessageBox API function instead of the MsgBox native VB function (this
way I was able to test my program while in the VB IDE).

Thanks again!


Leonardo Bosi
Proximity Soft
Buenos Aires, Argentina
--------------------------------------------
leobosi@proximity.com.ar
http://www.proximity.com.ar

[Leonardo Bosi]

Hello Sixto,

Thanks for your help, I solved my problem using that code. Note that I used
the MessageBox API function instead of the MsgBox native VB function (this
way I was able to test my program while in the VB IDE).

Thanks again!


Leonardo Bosi
Proximity Soft
Buenos Aires, Argentina
--------------------------------------------
leobosi@proximity.com.ar
http://www.proximity.com.ar

[Karl E. Peterson]

Hi Leonardo --

I wrote about this very problem in the Jan99 VBPJ. If you have that issue, pull it
out for the full commentary. Or, hit my site and download the TimedMsg.zip sample.
No need to go to the MessageBox API, unless you're not comfortable testing that
routine as an EXE.

Later... Karl
--
http://www.mvps.org/vb



"Leonardo Bosi" <leobosi@proximity.com.ar> wrote in message
news:3915eebe@news.devx.com...
> Hello,
>
> From my VB app, I have to show a message box (using the MsgBox native VB
> function, or one of the MessageBox API functions), and be able to remove the
> message box from my code when a Timer event occurs (if the user didn't close
> it until that moment). To achieve this, I thought I could get the handle to
> the message box window, in order to close that window (using either
> CloseWindow or DestroyWindow). So I'm asking: Is there a way for me to get
> the window handle for a message box I showed from my code? I read the
> documentation for the different API functions used to create message boxes
> (MessageBox, MessageBoxEx, MessageBoxIndirect), and didn't find in any of
> them a way for me to get that window handle...
>
> Any help would be appreciated...
>
> Thanks,
>
>
> Leonardo Bosi
> Proximity Soft
> Buenos Aires, Argentina
> --------------------------------------------
> leobosi@proximity.com.ar
> http://www.proximity.com.ar
>
>

[Karl E. Peterson]

Hi Leonardo --

I wrote about this very problem in the Jan99 VBPJ. If you have that issue, pull it
out for the full commentary. Or, hit my site and download the TimedMsg.zip sample.
No need to go to the MessageBox API, unless you're not comfortable testing that
routine as an EXE.

Later... Karl
--
http://www.mvps.org/vb



"Leonardo Bosi" <leobosi@proximity.com.ar> wrote in message
news:3915eebe@news.devx.com...
> Hello,
>
> From my VB app, I have to show a message box (using the MsgBox native VB
> function, or one of the MessageBox API functions), and be able to remove the
> message box from my code when a Timer event occurs (if the user didn't close
> it until that moment). To achieve this, I thought I could get the handle to
> the message box window, in order to close that window (using either
> CloseWindow or DestroyWindow). So I'm asking: Is there a way for me to get
> the window handle for a message box I showed from my code? I read the
> documentation for the different API functions used to create message boxes
> (MessageBox, MessageBoxEx, MessageBoxIndirect), and didn't find in any of
> them a way for me to get that window handle...
>
> Any help would be appreciated...
>
> Thanks,
>
>
> Leonardo Bosi
> Proximity Soft
> Buenos Aires, Argentina
> --------------------------------------------
> leobosi@proximity.com.ar
> http://www.proximity.com.ar
>
>

[Leonardo Bosi]

Hello Karl,

Yes, your sample was enough for me to solve my problem. It was recommended
by several fellows...

Thanks for your frequent contributions!

[Leonardo Bosi]

Hello Karl,

Yes, your sample was enough for me to solve my problem. It was recommended
by several fellows...

Thanks for your frequent contributions!