ListView Scroll Event

[Urs Vogel]

Hi

I'm looking for a way to trap the ListView's scroll events, in order to
control page-wise loading of not bindable data. Any hints of how to achieve
this?

Thanks, Urs

[Robin Tucker]

What you want is a "virtual list view". I don't see ListView as
particularly viable for this (I have tried it before). In the end I wrote
my own control which does the same and allows me to owner draw each row
(including images in cells).
"Urs Vogel" <uv****@msn.com> wrote in message
news:um*************@TK2MSFTNGP12.phx.gbl...

Hi

I'm looking for a way to trap the ListView's scroll events, in order to
control page-wise loading of not bindable data. Any hints of how to
achieve this?

Thanks, Urs

[Urs Vogel]

Thanks Robin

I'll inherit ListView and attach my own vertical scroll bar, using some API
calls to achieve some controllable and synchronized scrolling behaviour.

Urs

"Robin Tucker" <id*************************@reallyidont.com> schrieb im
Newsbeitrag news:cu*******************@news.demon.co.uk...

What you want is a "virtual list view". I don't see ListView as
particularly viable for this (I have tried it before). In the end I wrote
my own control which does the same and allows me to owner draw each row
(including images in cells).
"Urs Vogel" <uv****@msn.com> wrote in message
news:um*************@TK2MSFTNGP12.phx.gbl...

Hi

I'm looking for a way to trap the ListView's scroll events, in order to
control page-wise loading of not bindable data. Any hints of how to
achieve this?

Thanks, Urs

[Ken Tucker [MVP]]

Hi,

Use the native window class to listen for the scroll messages on
the listbox. Will work with any control.

' NativeWindow class to listen to operating system messages.

Private Class MyListener

Inherits NativeWindow

Public Event MyScroll(ByVal sender As Object, ByVal e As EventArgs)

Const WM_MOUSEACTIVATE = &H21

Const WM_MOUSEMOVE = &H200

Private ctrl As Control

Public Sub New(ByVal ctrl As Control)

AssignHandle(ctrl.Handle)

End Sub

Protected Overrides Sub WndProc(ByRef m As Message)

' Listen for operating system messages

Const WM_HSCROLL = &H114

Const WM_VSCROLL = &H115

If m.Msg = WM_Hscroll Or m.Msg = wm_vscroll Then

RaiseEvent MyScroll(ctrl, New EventArgs)

End If

MyBase.WndProc(m)

End Sub

Protected Overrides Sub Finalize()

ReleaseHandle()

MyBase.Finalize()

End Sub

End Class

Dim WithEvents sl As MyListener

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles MyBase.Load

sl = New MyListener(ListBox1)

end sub

Private Sub sl_MyScroll(ByVal sender As Object, ByVal e As System.EventArgs)
Handles sl.MyScroll

Me.Text = "Scroll"

End Sub


Ken

-------------------------------
"Urs Vogel" <uv****@msn.com> wrote in message
news:um*************@TK2MSFTNGP12.phx.gbl...
Hi

I'm looking for a way to trap the ListView's scroll events, in order to
control page-wise loading of not bindable data. Any hints of how to achieve
this?

Thanks, Urs