How to disable the numericupdown event firing?

[tommaso.gastaldi@uniroma1.it]

Hello,

A probably dumb question...

does anyone know hot to avoid that if one keep the mouse pressed on an
arrow of the numericUpDown it continues to fire events (it uses
evidently a timer) ?

I want 1 event for each click, and no timer activation. I have tried
using disable within the handler but does not work.

Any idea?

tommaso

[zacks@construction-imaging.com]

Re: How to disable the numericupdown event firing?

I assume you do not want the SelectedIndexCh anged event to only fire
once? Why not create a Boolean property in the Form's class, and
manipulate it with the MouseDown and MouseUp events to indicate the
state of the mousebutton. Then the SelectedIndexCh anged event can check
this property and if set, exit.

[tommaso.gastaldi@uniroma1.it]

Re: How to disable the numericupdown event firing?

hi!
thanks for the reply.
Checking mouse event can't do it, IMHO, as the mouse can ble clicked
out of the arrows, unless one knows how to detect that (?).

(I am not sure what you mean by "SelectedIndexC hanged ": I am using VB
2005 and I do not have this event for the "NumericUpDown" . Perhaps you
meant another control...).

Any other ideas?

-tommaso

[zacks@construction-imaging.com]

Re: How to disable the numericupdown event firing?

I was talking aout the MouseUp and MouseDown events for the numeric
updown control, which fire ONLY when you click on the numeric updown
controls buttons.

[zacks@construction-imaging.com]

Re: How to disable the numericupdown event firing?

I have used the NUD control and it most certainly has a
SelectedIndexCh anged event, which I use to change the value displayed
in a related textbox. If you are not using any of the NUD's events, I
don't see what your problem is.

[tommaso.gastaldi@uniroma1.it]

Re: How to disable the numericupdown event firing?

mmm, well there must be some misundertunding here.

I have just tried and the MouseDown and MouseUp events are raised even
if you do not click on the arrows of the NumericUpDown.
Further I am not able to find the "SelectedIndexC hanged" for the
NumericUpDown. Could you provide a pointer to the documentation where
it is dealt with?

At this point I am a little bit confused. I still think we are talking
about different things (perhaps you talk about a ComboBox ??)...

tommaso

[zacks@construction-imaging.com]

Re: How to disable the numericupdown event firing?

Sorry, my bad. Not SelectedIndexCh anged, ValueChanged.

ms-help://MS.VSCC.v80/MS.MSDN.v80/MS.NETDEVFX.v20 .en/CPref17/html/E_System_Window s_Forms_Numeric UpDown_ValueCha nged.htm

And you are right, to a degree. The MouseDown and MoustUp event do fire
if the mouse is simply somewhere over the control and the mouse button
is clicked, not when you click on one of the control's up or down
buttons. There may be some way to use them with the ValueChanged event
or some other event to accomplish your desired result.

[tommaso.gastaldi@uniroma1.it]

Re: How to disable the numericupdown event firing?

Yes. Let me explain further my problem, which actually I believe is a
BUG of the numericUpDown control which was already present in version
2003, and the VS team does not *seem* to have done anything about it.

ANYTIME you place any code under the ValueChanged event which take a
little while to execute (I do not mean a very long process [which could
justify for instance a new thread], but something within tens of a
second), if you keep the mouse clicked on one arrow you systematically,
that is ALWAYS get the following error:

----------------------------
System.NullRefe renceException was unhandled
Message="Object reference not set to an instance of an object."
Source="System. Windows.Forms"
StackTrace:
at
System.Windows. Forms.UpDownBas e.UpDownButtons .TimerHandler(O bject
source, EventArgs args)
at System.Windows. Forms.Timer.OnT ick(EventArgs e)
at System.Windows. Forms.Timer.Tim erNativeWindow. WndProc(Message &
m)
at System.Windows. Forms.NativeWin dow.DebuggableC allback(IntPtr
hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)
at
System.Windows. Forms.UnsafeNat iveMethods.Disp atchMessageW(MS G& msg)
at
System.Windows. Forms.Applicati on.ComponentMan ager.System.Win dows.Forms.Unsa feNativeMethods .IMsoComponentM anager.FPushMes sageLoop(Int32
dwComponentID, Int32 reason, Int32 pvLoopData)
at
System.Windows. Forms.Applicati on.ThreadContex t.RunMessageLoo pInner(Int32
reason, ApplicationCont ext context)
at
System.Windows. Forms.Applicati on.ThreadContex t.RunMessageLoo p(Int32
reason, ApplicationCont ext context)
at System.Windows. Forms.Applicati on.Run(Applicat ionContext
context)
at
Microsoft.Visua lBasic.Applicat ionServices.Win dowsFormsApplic ationBase.OnRun ()
at
Microsoft.Visua lBasic.Applicat ionServices.Win dowsFormsApplic ationBase.DoApp licationModel()
at
Microsoft.Visua lBasic.Applicat ionServices.Win dowsFormsApplic ationBase.Run(S tring[]
commandLine)
at Trial.My.MyAppl ication.Main(St ring[] Args) in
17d14f5c-a337-4978-8281-53493378c1071.v b:line 81
------------------

and there seems anything one can do about it.

That's why I wished to disable the associated timer. Because it causes
an exception I cannot do anything about.

If anyone has suggestion to solve this annoying problem (and I do hope
someone of the VS team is listening) I would like to know.

tommaso

[zacks@construction-imaging.com]

Re: How to disable the numericupdown event firing?

Hmm, you know, the app I wrote that uses the NUD control does some
calculations in the ValueChanged event, and I can hold down either the
up or the down button, and I have never (so far) gotten the exception
you get. The calculations are not intense, but are not trivial either.
Maybe I will test it and see if I can re-create your problem.

[tommaso.gastaldi@uniroma1.it]

Re: How to disable the numericupdown event firing?

It doesn't take much to reproduce the bug. It is crucial (to get the
exception) that
the called routine allows events (DOEVENTS). I get systematically this
exception
when drawing something within the ValueChanged event.

Here is the BUG demo code. Just create a form with a NumericUpDown and
paste the code.
Run the program. Click on the UP arrow and keep pressed. You will get
the exception very soon.
I don't go beyond 11.

'--------------------------------begin code

Public Class Form1

Private Sub Form1_Load(ByVa l sender As System.Object, ByVal e As
System.EventArg s) Handles MyBase.Load
Me.NumericUpDow n1.Maximum = Decimal.MaxValu e
End Sub

Private Sub NumericUpDown1_ ValueChanged(By Val sender As
System.Object, ByVal e As System.EventArg s) Handles
NumericUpDown1. ValueChanged
Me.SomeTaskWith Events()
End Sub

Sub SomeTaskWithEve nts()
System.Threadin g.Thread.Sleep( 10)
Application.DoE vents()
End Sub

End Class

'--------------------------------end code




- Details

System.NullRefe renceException was unhandled
Message="Object reference not set to an instance of an object."
Source="System. Windows.Forms"
StackTrace:
at
System.Windows. Forms.UpDownBas e.UpDownButtons .TimerHandler(O bject
source, EventArgs args)
at System.Windows. Forms.Timer.OnT ick(EventArgs e)
at System.Windows. Forms.Timer.Tim erNativeWindow. WndProc(Message &
m)
at System.Windows. Forms.NativeWin dow.DebuggableC allback(IntPtr
hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)
at
System.Windows. Forms.UnsafeNat iveMethods.Disp atchMessageW(MS G& msg)
at
System.Windows. Forms.Applicati on.ComponentMan ager.System.Win dows.Forms.Unsa feNativeMethods .IMsoComponentM anager.FPushMes sageLoop(Int32
dwComponentID, Int32 reason, Int32 pvLoopData)
at
System.Windows. Forms.Applicati on.ThreadContex t.RunMessageLoo pInner(Int32
reason, ApplicationCont ext context)
at
System.Windows. Forms.Applicati on.ThreadContex t.RunMessageLoo p(Int32
reason, ApplicationCont ext context)
at System.Windows. Forms.Applicati on.DoEvents()
at BUGNUD.Form1.So meTaskWithEvent s() in C:\Documents and
Settings\User\D ocumenti\Visual Studio
2005\Projects\B UGNUD\BUGNUD\Fo rm1.vb:line 13
at BUGNUD.Form1.Nu mericUpDown1_Va lueChanged(Obje ct sender,
EventArgs e) in C:\Documents and Settings\User\D ocumenti\Visual Studio
2005\Projects\B UGNUD\BUGNUD\Fo rm1.vb:line 8
at System.Windows. Forms.NumericUp Down.OnValueCha nged(EventArgs
e)
.....

[Dennis]

Re: How to disable the numericupdown event firing?

In the mouse down event, use the "Remove Handler" to remove the ValueChanged
Event handler then in the MouseUp event, use the Add Handler to restore event
handling in the Value Changed Event. This should work.
--
Dennis in Houston


"tommaso.gastal di@uniroma1.it" wrote:
[color=blue]
> It doesn't take much to reproduce the bug. It is crucial (to get the
> exception) that
> the called routine allows events (DOEVENTS). I get systematically this
> exception
> when drawing something within the ValueChanged event.
>
> Here is the BUG demo code. Just create a form with a NumericUpDown and
> paste the code.
> Run the program. Click on the UP arrow and keep pressed. You will get
> the exception very soon.
> I don't go beyond 11.
>
> '--------------------------------begin code
>
> Public Class Form1
>
> Private Sub Form1_Load(ByVa l sender As System.Object, ByVal e As
> System.EventArg s) Handles MyBase.Load
> Me.NumericUpDow n1.Maximum = Decimal.MaxValu e
> End Sub
>
> Private Sub NumericUpDown1_ ValueChanged(By Val sender As
> System.Object, ByVal e As System.EventArg s) Handles
> NumericUpDown1. ValueChanged
> Me.SomeTaskWith Events()
> End Sub
>
> Sub SomeTaskWithEve nts()
> System.Threadin g.Thread.Sleep( 10)
> Application.DoE vents()
> End Sub
>
> End Class
>
> '--------------------------------end code
>
>
>
>
> - Details
>
> System.NullRefe renceException was unhandled
> Message="Object reference not set to an instance of an object."
> Source="System. Windows.Forms"
> StackTrace:
> at
> System.Windows. Forms.UpDownBas e.UpDownButtons .TimerHandler(O bject
> source, EventArgs args)
> at System.Windows. Forms.Timer.OnT ick(EventArgs e)
> at System.Windows. Forms.Timer.Tim erNativeWindow. WndProc(Message &
> m)
> at System.Windows. Forms.NativeWin dow.DebuggableC allback(IntPtr
> hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)
> at
> System.Windows. Forms.UnsafeNat iveMethods.Disp atchMessageW(MS G& msg)
> at
> System.Windows. Forms.Applicati on.ComponentMan ager.System.Win dows.Forms.Unsa feNativeMethods .IMsoComponentM anager.FPushMes sageLoop(Int32
> dwComponentID, Int32 reason, Int32 pvLoopData)
> at
> System.Windows. Forms.Applicati on.ThreadContex t.RunMessageLoo pInner(Int32
> reason, ApplicationCont ext context)
> at
> System.Windows. Forms.Applicati on.ThreadContex t.RunMessageLoo p(Int32
> reason, ApplicationCont ext context)
> at System.Windows. Forms.Applicati on.DoEvents()
> at BUGNUD.Form1.So meTaskWithEvent s() in C:\Documents and
> Settings\User\D ocumenti\Visual Studio
> 2005\Projects\B UGNUD\BUGNUD\Fo rm1.vb:line 13
> at BUGNUD.Form1.Nu mericUpDown1_Va lueChanged(Obje ct sender,
> EventArgs e) in C:\Documents and Settings\User\D ocumenti\Visual Studio
> 2005\Projects\B UGNUD\BUGNUD\Fo rm1.vb:line 8
> at System.Windows. Forms.NumericUp Down.OnValueCha nged(EventArgs
> e)
> .....
>
>[/color]

[tommaso.gastaldi@uniroma1.it]

Re: How to disable the numericupdown event firing?

hi Dennis,

MouseUp/Down cannot be used to place semaphores or detach handlers as
they are fired even when the mouse is clicked on an area of the NUD
different from arrows.

Further, the ValueChanged is executed under a handles clause and cannot
be removed that way,...

Could you actually show your suggestion applied to the Bug code?

tommaso

[Dennis]

Re: How to disable the numericupdown event firing?

MouseUp/Down events CAN be used to remove/add handlers. The following works
except that the ValueChanged event is fired ONCE before the mousedown event
is fired when the mouse button is held down.

Private Sub NumericUpDown1_ ValueChanged(By Val sender As System.Object, ByVal
e As System.EventArg s) Handles NumericUpDown1. ValueChanged

'Will fire one time when the mouse is pressed and held then not fire
again until the function is called from the MouseUp event.

End Sub

Private Sub NumericUpDown1_ MouseDown(ByVal sender As Object, ByVal e As
System.Windows. Forms.MouseEven tArgs) Handles NumericUpDown1. MouseDown
RemoveHandler NumericUpDown1. ValueChanged, AddressOf
NumericUpDown1_ ValueChanged

End Sub

Private Sub NumericUpDown1_ MouseUp(ByVal sender As Object, ByVal e As
System.Windows. Forms.MouseEven tArgs) Handles NumericUpDown1. MouseUp
AddHandler NumericUpDown1. ValueChanged, AddressOf
NumericUpDown1_ ValueChanged
Dim e1 As New System.EventArg s
'NumericUpDown1 _ValueChanged(s ender, e1)
End Sub
--
Dennis in Houston


"tommaso.gastal di@uniroma1.it" wrote:
[color=blue]
> hi Dennis,
>
> MouseUp/Down cannot be used to place semaphores or detach handlers as
> they are fired even when the mouse is clicked on an area of the NUD
> different from arrows.
>
> Further, the ValueChanged is executed under a handles clause and cannot
> be removed that way,...
>
> Could you actually show your suggestion applied to the Bug code?
>
> tommaso
>
>[/color]

[tommaso.gastaldi@uniroma1.it]

Re: How to disable the numericupdown event firing?

Good! You are right.

You are almost there. There seems to be a last problem. If one clicks
on UpArrow and release the mouse and repeat this process starting, for
instance, from 1, the ValueChanged events is fired only for the odd
numbers. That is in a sequence of clicks only half of them rise the
ValueChanged event. But one would like to get the event for each
click...

Any idea?

tommaso

[tommaso.gastaldi@uniroma1.it]

Re: How to disable the numericupdown event firing?

mmm, I am afraid that this isn't the right approach. There seems to be
no way to make it work right.
Perhaps another approach could be working by reflection and disabling
the internal timer.
But, It would probably be easier to create a custom NUD!

Such a small control is so defective! I still do not understand how
come takes so long (years) to fix it !

-t