If the control has no scroll bars the OffsetChanged and OversizeChanged events are not fired. Use the ScrollBars property of the control to determine which scroll bars are visible within the control. Use the ScrollButtonClick event to notify your application that the user clicks a button in the control's scrollbar. Use the ScrolPartCaption property to specify the caption of the scroll's part. Use the ScrollToolTip property to specify the tooltip being displayed when the user clicks and moves the scrollbar's thumb. Use the Background property to change the visual appearance for any part in the control's scroll bar.

The following VB sample displays the new scroll position when user scrolls horizontally the control:

Private Sub Tree1_OffsetChanged(ByVal Horizontal As Boolean, ByVal NewVal As Long)
    If (Horizontal) Then
        Debug.Print "The horizontal scroll bar has been moved to " & NewVal
    End If
End Sub

The following VC sample displays the new scroll position when the user scrolls vertically the control:

void OnOffsetChangedTree1(BOOL Horizontal, long NewVal) 
{
	if ( !Horizontal )
	{
		CString strFormat;
		strFormat.Format( "NewPos = %i\n", NewVal );
		OutputDebugString( strFormat );
	}
}

The following VB.NET sample displays the new scroll position when the user scrolls vertically the control:

Private Sub AxTree1_OffsetChanged(ByVal sender As Object, ByVal e As AxEXTREELib._ITreeEvents_OffsetChangedEvent) Handles AxTree1.OffsetChanged
    If (Not e.horizontal) Then
        Debug.WriteLine(e.newVal)
    End If
End Sub

The following C# sample displays the new scroll position when the user scrolls vertically the control:

private void axTree1_OffsetChanged(object sender, AxEXTREELib._ITreeEvents_OffsetChangedEvent e)
{
	if ( !e.horizontal )
		System.Diagnostics.Debug.WriteLine(e.newVal);
}

The following VFP sample displays the new scroll position when the user scrolls vertically the control:

*** ActiveX Control Event ***
LPARAMETERS horizontal, newval

if ( 0 # horizontal )
	wait window nowait str( newval )
endif