winform上下滚动公告【代码】

        private void messageTimer_Tick(object sender, EventArgs e)
        {
            foreach (Label obj in this.panel1.Controls)
            {
                if (obj.Top <= (-LBLHEIGHT))
                {
                    obj.Top = obj.Top + (rowcount + 1) * LBLHEIGHT - obj.Height;
                }
                else
                {
                    obj.Top = obj.Top - 1;
                }
            }
        }