class MyListView : ListView
{
        public bool Scflag = false;
        public double Speed = 1.0f;
        ListViewItem _scrItm;
        int _index;
        public async Task AutoScrollAsync()
        {
            Scflag = !Scflag;
            while (Scflag)
            {
                mv(mvP());
                await Task.Delay(16);
            }
            Scflag = false;
        }

        private double mvP()
        {
            _index = (int)_sv.VerticalOffset - 2;
            _scrItm = this.ContainerFromIndex(_index) as ListViewItem;
            return Speed / _scrItm.ActualHeight;
        }

        private void mv(double p)
        {
            _sv.ChangeView(null, _sv.VerticalOffset  + p, null);
            _sv.UpdateLayout();
        }
}