void viewport_VScrollChanged(object sender, UIScrollEventArgs e)
{
if (VScrollChanged != null)
{
VScrollChanged.Invoke(sender, e);
}
}
/// <summary>
/// The list's window procedure.
/// </summary>
/// <param name="m">A Windows Message Object.</param>
protected override void WndProc(ref Message m)
{
if (m.Msg == LB_ADDSTRING ||
m.Msg == LB_INSERTSTRING ||
m.Msg == LB_DELETESTRING ||
m.Msg == LB_RESETCONTENT)
{
ItemsChanged?.Invoke(this, new EventArgs());
}
// if the message indicates that the TopIndex property of the list box might have changed, raise the VScrollChanged event..
if (m.Msg == WM_VSCROLL || m.Msg == WM_MOUSEWHEEL || m.Msg == WM_KEYDOWN)
{
// ..if not denied and the TopIndex property was actually changed..
if (lastTopIndex != this.TopIndex)
{
lastTopIndex = TopIndex; // save the top index so it's changes can be monitored..
// if the VScrollChanged event is subscribed the raise the event with (FromControl = true)..
VScrollChanged?.Invoke(this, new VScrollChangedEventArgs()
{
Minimum = 0, Maximum = Items.Count, Value = VScrollPosition, FromControl = true
});
}
}
base.WndProc(ref m);
}
public void RaiseProperEvents(UIScrollEventArgs hScrollEventArgs, UIScrollEventArgs vScrollEventArgs)
{
if (this.VScrollChanged != null && vScrollEventArgs != null)
{
VScrollChanged.Invoke(owner, vScrollEventArgs);
}
if (this.HScrollChanged != null && hScrollEventArgs != null)
{
HScrollChanged.Invoke(owner, hScrollEventArgs);
}
}
/// <summary>
/// The WndProc is overridden so some messages can be used to raise the VScrollChanged event.
/// </summary>
/// <param name="m">A reference to a Message class instance.</param>
protected override void WndProc(ref Message m)
{
base.WndProc(ref m); // first call the base WndProc..
// .. and if the message indicates that the TopIndex property of the list box might have changed, raise the VScrollChanged event..
if (m.Msg == WM_VSCROLL || m.Msg == WM_MOUSEWHEEL || m.Msg == WM_KEYDOWN)
{
// ..if not denied and the TopIndex property was actually changed..
if (!noEvent && lastTopIndex != this.TopIndex)
{
lastTopIndex = TopIndex; // save the top index so it's changes can be monitored..
// if the VScrollChanged event is subscribed the raise the event with (FromControl = true)..
VScrollChanged?.Invoke(this, new VScrollChangedEventArgs()
{
Minimum = 0, Maximum = VScrollMaximum, Value = VScrollPosition, FromControl = true
});
}
}
}
