Tom
Fri Jul 04 05:42:29 CDT 2003
Glad you've got it sorted!!
> > "Notes to Inheritors: When overriding the ProcessKeyPreview method in a
> > derived class, a control should return true to indicate that it has
> > processed the key. For keys that are not processed by the control, the
> > result of calling the base class's ProcessKeyEventArgs method should be
> > returned."
Technically this is correct, though I see why you might find it confusing.
It's all about how the new events in VB are delegate methods. It simply
means call the base class' version of the method to make sure it gets
notified of the message.
--
Happy to help,
-- Tom Spink
(thomas.spink@ntlworld.com)
" There's no place like 127.0.0.1 "
Please respond to the newsgroup,
so all can benefit.
One Day,
"Ali Eghtebas" <ali.e@home.se> wrote in message
news:#mQkPgbQDHA.2316@TK2MSFTNGP12.phx.gbl...
> The issue was solved by overriding ProcessCmdKey instead ;)
> This might be an issue in .Net Framework 1.1.
> --
> Regards
> Ali Eghtebas Sweden
>
> "Ali Eghtebas" <ali.e@home.se> wrote in message
> news:e6d6FZaQDHA.1552@TK2MSFTNGP10.phx.gbl...
> > > > 1) Why can't I trap the KEYDOWN while I can trap KEYUP?
> > > ??? Whats happening when you try to trap keydown?
> >
> > Actually what happens is that nothing happens since the execution never
> gets
> > into the If-Statement where I want to replace the Enter key with Tab
key.
> > NOTE that I use .Net Framework 1.1.
> > This must be a bug or something since according to the documentation I
> > should be able to trap both KEYDOWN and KEYUP, which seems to only apply
> on
> > KEYUP in this case.
> > To be more specifik m.Msg = WM_KEYUP returns True while m.Msg =
WM_KEYDOWN
> > returns FALSE!
> >
> > > > 3) Many examples in the newsgroups use Return
> > MyBase.ProcessKeyPreview(m)
> > > as
> > > > the last code line while I have used Return
> > MyBase.ProcessKeyEventArgs(m)
> > > > according to the MSDN, is this correct or is it a typo in MSDN?
(watch
> > for
> > > > line breaks in the url)
> > >
> > > I can't see where ProcessKeyEventArgs appears anywhere, but it's wrong
> > > anyway. It should be:
> > >
> > > Return MyBase.ProcessKeyPreview(m)
> > >
> > > This is because you are overriding the function, and so you are now
> > letting
> > > the original function process the key. The original function, that you
> > > overrode, is not called, because you have overridden it, so calling
that
> > > line will call the original function and return the value that the
> > original
> > > function would have done.
> > >
> > > (I hope that make sense)
> >
> >
> > This makes sence to me and that is also what I thought but the only
> > confusing thing about it is MSDN:
> > "Notes to Inheritors: When overriding the ProcessKeyPreview method in a
> > derived class, a control should return true to indicate that it has
> > processed the key. For keys that are not processed by the control, the
> > result of calling the base class's ProcessKeyEventArgs method should be
> > returned."
> >
> > > Also, just FYI, Theres a better way to select the next control in a
> form,
> > > other than sending the 'Tab' key (if you've seen my post about
> simulating
> > > keystrokes earlier you'll realise I think it's bad). If you look at
the
> > > Me.SelectNextControl method, you can select the next control, based on
> the
> > > ActiveControl:
> > >
> > > Me.SelectNextControl(Me.ActiveControl, True)
> > >
> > > More information on this:
> > > <WatchForWrapping>
> > >
> >
>
ms-help://MS.VSCC/MS.MSDNVS/cpref/html/frlrfsystemwindowsformscontrolclassse
> > > lectnextcontroltopic.htm
> > > </WatchForWrapping>
> >
> > The reason I want to replace the Enter Key with Tab is not that I want
> give
> > the focus to the next control on my form. I do this since in the last
row
> in
> > a DataGrid when editing a Cell the Enter Key doesn't assign the new
value
> to
> > the Cell since this is the last row and hence there is no next row to
move
> > the focus on. I simply send Replace the Enter with Tab there to make the
> > change in the Cell and trigger other code within
> > CurrentCellChanged.
> >
> > > One Day,
> > > "Ali Eghtebas" <ali.e@home.se> wrote in message
> > > news:eO$GXlZQDHA.3796@tk2msftngp13.phx.gbl...
> > > > Hi,
> > > >
> > > > I have 3 questions regarding the code below:
> > > >
> > > > 1) Why can't I trap the KEYDOWN while I can trap KEYUP?
> > > > 2) Is it correct that I use Return True within the IF-Statement?
(I've
> > > > already read the documentation but it is rather hard to understand
so
> > > please
> > > > don't refer to it :)
> > > > 3) Many examples in the newsgroups use Return
> > MyBase.ProcessKeyPreview(m)
> > > as
> > > > the last code line while I have used Return
> > MyBase.ProcessKeyEventArgs(m)
> > > > according to the MSDN, is this correct or is it a typo in MSDN?
(watch
> > for
> > > > line breaks in the url)
> > > >
> > > >
> > >
> >
>
ms-help://MS.VSCC/MS.MSDNVS/cpref/html/frlrfsystemwindowsformscontrolclasspr
> > > > ocesskeypreviewtopic.htm
> > > >
> > > > I aslo wonder if my code is correct as to subtitude Enter key with
Tab
> > in
> > > a
> > > > specifik column of the a datagrid. It seems to function well when
> > trapping
> > > > the WM_KEYUP but to get the desired effect I need
> > > > to trap the WM_KEYDOWN, and doesn't work!
> > > >
> > > > Protected Overrides Function ProcessKeyPreview(ByRef m As
> > > > System.Windows.Forms.Message) As Boolean
> > > > Dim keyCode As Keys = CType(m.WParam.ToInt32, Keys) And
> > > Keys.KeyCode
> > > > Const WM_KEYDOWN As Integer = &H100
> > > > Const WM_KEYUP As Integer = &H101
> > > >
> > > > If m.Msg = WM_KEYDOWN AndAlso keyCode = Keys.Enter _
> > > > AndAlso DataGridColumnStyle1.TextBox Is ActiveControl _
> > > > AndAlso DataGrid1.DataSource.GetType Is GetType(DataView)
Then
> > > > SendKeys.Send("{Tab}")
> > > > Return True
> > > > End If
> > > > Return MyBase.ProcessKeyEventArgs(m)
> > > > End Function
> > > >
> > > > --
> > > > Thanks in advance
> > > > Ali Eghtebas Sweden
> >
> >
>
>