private void button1_Click_1(object sender, EventArgs e) { ListBox.ObjectCollection list = PlayList.Items; Random random = new Random(); int w = list.Count; PlayList.BeginUpdate(); while (w > 1) { w--; int u = random.Next(w + 1); object value = list[u]; list[u] = list[w]; list[w] = value; } PlayList.EndUpdate(); PlayList.Invalidate(); }