"yxq" <gayxq@163.net> wrote in message
news:ewQxzMs3EHA.2404@TK2MSFTNGP14.phx.gbl...
> Hello,
> There are some items in ListView1, but error will occur in the code below,
> why? Thank you.
>
> ****************************************************************
> Private Sub ListView1_SelectedIndexChanged(ByVal sender As Object, ByVal e
> As System.EventArgs) Handles ListView1.SelectedIndexChanged
> MessageBox.Show(ListView1.SelectedItems(0).Index)
> End Sub
>

> Hello,
> There are some items in ListView1, but error will occur in the code below,
> why? Thank you.
>
> ****************************************************************
> Private Sub ListView1_SelectedIndexChanged(ByVal sender As Object, ByVal e
> As System.EventArgs) Handles ListView1.SelectedIndexChanged
> MessageBox.Show(ListView1.SelectedItems(0).Index)
> End Sub
>

"Mike McIntyre" <mikemc@dotnetshowandtell.com> wrote in message
news:e0q4G0s3EHA.3504@TK2MSFTNGP12.phx.gbl...
> What is the error?
>
>
> --
> Mike
>
> Mike McIntyre
> Visual Basic MVP
> www.getdotnetcode.com
>
> "yxq" <gayxq@163.net> wrote in message
> news:ewQxzMs3EHA.2404@TK2MSFTNGP14.phx.gbl...
> > Hello,
> > There are some items in ListView1, but error will occur in the code
below,
> > why? Thank you.
> >
> > ****************************************************************
> > Private Sub ListView1_SelectedIndexChanged(ByVal sender As Object, ByVal
e
> > As System.EventArgs) Handles ListView1.SelectedIndexChanged
> > MessageBox.Show(ListView1.SelectedItems(0).Index)
> > End Sub
> >
>

> Yes I've had that. At the instance of selecting, the event is fired with
> no
> items selected. I got round it by putting in a catch at the top
>
> If listview1.SelectedItems = 0 then Exit Sub

> There are some items in ListView1, but error will occur in the code below,
> why? Thank you.
>
> ****************************************************************
> Private Sub ListView1_SelectedIndexChanged(ByVal sender As Object, ByVal e
> As System.EventArgs) Handles ListView1.SelectedIndexChanged
> MessageBox.Show(ListView1.SelectedItems(0).Index)
> End Sub

On 2004-12-11, Jerry Spence1 <jerry.spence@somewhere.com> wrote:
>
>> ... should read 'ListView1.SelectedItems.Count > 0'...
>>
>> --
>> Herfried K. Wagner [MVP]
>> <URL:http://dotnet.mvps.org/>
>>
> I think I was right the first time. If there are no selected items, then get
> out. It happens when the event fires for the first time.

> "yxq" <gayxq@163.net> schrieb:
>> There are some items in ListView1, but error will occur in the code
>> below, why? Thank you.
>>
>> ****************************************************************
>> Private Sub ListView1_SelectedIndexChanged(ByVal sender As Object, ByVal
>> e As System.EventArgs) Handles ListView1.SelectedIndexChanged
>> MessageBox.Show(ListView1.SelectedItems(0).Index)
>> End Sub
>
> That's not a bug. It's a feature.
>
> When the user initiates a selection change that effectively results in all
> selected items being deselected and then one or more items being
> (re)selected, the control will raise the event twice, first for
> deselecting the items and then for selecting them again (although the user
> will only see that as a single operation). You can avoid the exception by
> extending your code like this:
>
> \\\
> Dim SourceControl As ListView = DirectCast(sender, ListView)
> If SourceControl.SelectedItems.Length > 0 Then
> ...
> End If
> ///
>
> --
> Herfried K. Wagner [MVP]
> <URL:http://dotnet.mvps.org/>
>

> ... should read 'ListView1.SelectedItems.Count > 0'...
>
> --
> Herfried K. Wagner [MVP]
> <URL:http://dotnet.mvps.org/>
>

>>> ... should read 'ListView1.SelectedItems.Count > 0'...
>>
>> I think I was right the first time. If there are no selected items, then
>> get
>> out. It happens when the event fires for the first time.
>
> Of course, your original code snippet does have the minor disadvantage
> of not compiling. That can be a detriment in certain applications.
>
> :)