listbox's SelectedIndexChanged keep fire

27 Nov 2006 5:46 PM

martin1

Hi, All,

I want user select first item (called All) in listbox, then all other items
are selected by SetSelected method, but in loop (see code below) whenever
going to SetSelected(), the SelectedIndexChanged event keep fire and loop
doesn't go to next, finally the program stop at infinite loop.

Sub lstCem_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles lstCem.SelectedIndexChanged
If lstCem.GetSelected(0) = True Then
           For i = 1 To (lstCem.Items.Count - 1)
                      lstCem.SetSelected(i, True)
           Next
end if
End Sub

can anyone help thisout?
Thanks,
Marin

27 Nov 2006 8:52 PM

Ken Tucker [MVP]

Hi,

    Try something like this

Private Sub ListBox1_SelectedIndexChanged(ByVal sender As Object, ByVal e
As System.EventArgs) Handles ListBox1.SelectedIndexChanged
        Static boolRunning As Boolean = False

        If ListBox1.GetSelected(0) = True And Not boolRunning Then
            boolRunning = True
            For i As Integer = 1 To (ListBox1.Items.Count - 1)
                ListBox1.SetSelected(i, True)
            Next
            boolRunning = False
        End If

Ken
-------------------

Show quoteHide quote

"martin1" wrote:

> Hi, All,
>
> I want user select first item (called All) in listbox, then all other items
> are selected by SetSelected method, but in loop (see code below) whenever
> going to SetSelected(), the SelectedIndexChanged event keep fire and loop
> doesn't go to next, finally the program stop at infinite loop.
>
> Sub lstCem_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As
> System.EventArgs) Handles lstCem.SelectedIndexChanged
> If lstCem.GetSelected(0) = True Then
>            For i = 1 To (lstCem.Items.Count - 1)
>                       lstCem.SetSelected(i, True)
>            Next
> end if
> End Sub
>
> can anyone help thisout?
> Thanks,
> Marin

28 Nov 2006 12:27 AM

Dennis

Using a static variable works as does a global. However, for general use,
you might try "RemoveHandler", do your thing, then "AddHandler". This will
prevent the event from firing while you "do your thing".

--
Dennis in Houston

Show quoteHide quote

"martin1" wrote:

> Hi, All,
>
> I want user select first item (called All) in listbox, then all other items
> are selected by SetSelected method, but in loop (see code below) whenever
> going to SetSelected(), the SelectedIndexChanged event keep fire and loop
> doesn't go to next, finally the program stop at infinite loop.
>
> Sub lstCem_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As
> System.EventArgs) Handles lstCem.SelectedIndexChanged
> If lstCem.GetSelected(0) = True Then
>            For i = 1 To (lstCem.Items.Count - 1)
>                       lstCem.SetSelected(i, True)
>            Next
> end if
> End Sub
>
> can anyone help thisout?
> Thanks,
> Marin

28 Nov 2006 3:59 PM

martin1

Hi, Dannis,

I tried addhander and one task (see below code) called toggle "all cems on"
works, but another 2 tasks: 1) ' toggle "all Cems" off , and 2) ' toggle "all
Cems" off if a cem is deselected, are not work. the task 1) is is if user
deselect first item called All Cems, then all other cem deselect, the task
2) is if any one but first one deselect, then the first one (called all cems)
is deselect. I think selectIndex logic may wrong but don't know how to fix
that. Any more advice? Thanks for your time.

Private Sub lstCem_SelectedIndexChanged(ByVal sender As System.Object, ByVal
e As System.EventArgs) Handles lstCem.SelectedIndexChanged

        Dim lstItem As Short
        Dim i As Short
        Static boolRunning As Boolean = False

        RemoveHandler lstCem.SelectedIndexChanged, AddressOf
Me.lstCem_SelectedIndexChanged

        lstItem = lstCem.SelectedIndex
        If lstItem = 0 Then
            'toggle "all Cems" on
            If lstCem.GetSelected(0) = True Then
                For i = 1 To (lstCem.Items.Count - 1)
                    lstCem.SetSelected(i, True)
                Next
                ' toggle "all Cems" off
            ElseIf lstCem.GetSelected(0) = False Then
                For i = 1 To (lstCem.Items.Count - 1)
                    lstCem.SetSelected(i, False)
                Next
                'boolRunning = False
                lstCem.SelectedIndex = 0 ' put list index back
            End If
            'boolRunning = False
        Else
            ' toggle "all Cems" off if a cem is deselected
            If lstCem.GetSelected(lstItem) = False Then

                lstCem.SetSelected(0, False)
                lstCem.SelectedIndex = lstItem ' put list index back
            End If
        End If

        AddHandler lstCem.SelectedIndexChanged, AddressOf
Me.lstCem_SelectedIndexChanged
    End Sub

Show quoteHide quote

"Dennis" wrote:

> Using a static variable works as does a global. However, for general use,
> you might try "RemoveHandler", do your thing, then "AddHandler". This will
> prevent the event from firing while you "do your thing".
> --
> Dennis in Houston
>
>
> "martin1" wrote:
>
> > Hi, All,
> >
> > I want user select first item (called All) in listbox, then all other items
> > are selected by SetSelected method, but in loop (see code below) whenever
> > going to SetSelected(), the SelectedIndexChanged event keep fire and loop
> > doesn't go to next, finally the program stop at infinite loop.
> >
> > Sub lstCem_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As
> > System.EventArgs) Handles lstCem.SelectedIndexChanged
> > If lstCem.GetSelected(0) = True Then
> >            For i = 1 To (lstCem.Items.Count - 1)
> >                       lstCem.SetSelected(i, True)
> >            Next
> > end if
> > End Sub
> >
> > can anyone help thisout?
> > Thanks,
> > Marin

13 Dec 2006 6:42 PM

DanielReis

Try this:

Private Sub ListBox1_SelectedIndexChanged(ByVal sender As System.Object,
ByVal e As System.EventArgs) Handles ListBox1.SelectedIndexChanged
        If ListBox1.SelectedIndex() = 0
            Dim SIC As New ListBox.SelectedIndexCollection(ListBox1)
            For I = 0 To ListBox1.Items.Count - 1
                SIC.Add(I)
            Next
        End If
End Sub

DanyR

Show quoteHide quote

"martin1" wrote:

> Hi, Dannis,
>
> I tried addhander and one task (see below code) called toggle "all cems on"
> works, but another 2 tasks: 1) ' toggle "all Cems" off , and 2) ' toggle "all
> Cems" off if a cem is deselected, are not work. the task 1) is is if user
> deselect first item called All Cems, then all other cem deselect, the task
> 2) is if any one but first one deselect, then the first one (called all cems)
> is deselect. I think selectIndex logic may wrong but don't know how to fix
> that. Any more advice? Thanks for your time.
>
>
> Private Sub lstCem_SelectedIndexChanged(ByVal sender As System.Object, ByVal
> e As System.EventArgs) Handles lstCem.SelectedIndexChanged
>
>         Dim lstItem As Short
>         Dim i As Short
>         Static boolRunning As Boolean = False
>
>         RemoveHandler lstCem.SelectedIndexChanged, AddressOf
> Me.lstCem_SelectedIndexChanged
>
>         lstItem = lstCem.SelectedIndex
>         If lstItem = 0 Then
>             'toggle "all Cems" on
>             If lstCem.GetSelected(0) = True Then
>                 For i = 1 To (lstCem.Items.Count - 1)
>                     lstCem.SetSelected(i, True)
>                 Next
>                 ' toggle "all Cems" off
>             ElseIf lstCem.GetSelected(0) = False Then
>                 For i = 1 To (lstCem.Items.Count - 1)
>                     lstCem.SetSelected(i, False)
>                 Next
>                 'boolRunning = False
>                 lstCem.SelectedIndex = 0 ' put list index back
>             End If
>             'boolRunning = False
>         Else
>             ' toggle "all Cems" off if a cem is deselected
>             If lstCem.GetSelected(lstItem) = False Then
>
>                 lstCem.SetSelected(0, False)
>                 lstCem.SelectedIndex = lstItem ' put list index back
>             End If
>         End If
>
>         AddHandler lstCem.SelectedIndexChanged, AddressOf
> Me.lstCem_SelectedIndexChanged
>     End Sub
>
> "Dennis" wrote:
>
> > Using a static variable works as does a global. However, for general use,
> > you might try "RemoveHandler", do your thing, then "AddHandler". This will
> > prevent the event from firing while you "do your thing".
> > --
> > Dennis in Houston
> >
> >
> > "martin1" wrote:
> >
> > > Hi, All,
> > >
> > > I want user select first item (called All) in listbox, then all other items
> > > are selected by SetSelected method, but in loop (see code below) whenever
> > > going to SetSelected(), the SelectedIndexChanged event keep fire and loop
> > > doesn't go to next, finally the program stop at infinite loop.
> > >
> > > Sub lstCem_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As
> > > System.EventArgs) Handles lstCem.SelectedIndexChanged
> > > If lstCem.GetSelected(0) = True Then
> > >            For i = 1 To (lstCem.Items.Count - 1)
> > >                       lstCem.SetSelected(i, True)
> > >            Next
> > > end if
> > > End Sub
> > >
> > > can anyone help thisout?
> > > Thanks,
> > > Marin