private void delectToolStripMenuItem_Click(object sender, EventArgs e) { ListBox.SelectedIndexCollection selectedindexs = new ListBox.SelectedIndexCollection(lb_config); selectedindexs = lb_config.SelectedIndices; int cout = selectedindexs.Count; for (int i = 0; i < selectedindexs.Count; ) lb_config.Items.RemoveAt(selectedindexs[i]); }