C#实现ListView选中项向上或向下移动的方法

private void buttonUp_Click(object sender, EventArgs e) {   if (listView.SelectedItems.Count > 0 && listView.SelectedItems[0].Index != 0)   {     listView.BeginUpdate();     foreach (ListViewItem lvi in listView.SelectedItems)     {       ListViewItem item = lvi;       int index = lvi.Index;       listView.Items.RemoveAt(index);       listView.Items.Insert(index - 1, item);     }     listView.EndUpdate();   }   listView.Focus(); } private void buttonDown_Click(object sender, EventArgs e) {   if (listView.SelectedItems.Count > 0 && listView.SelectedItems[listView.SelectedItems.Count - 1].Index < (listView.Items.Count-1))   {     listView.BeginUpdate();     int count = listView.SelectedItems.Count;     foreach (ListViewItem lvi in listView.SelectedItems)     {       ListViewItem item = lvi;       int index = lvi.Index;       listView.Items.RemoveAt(index);       listView.Items.Insert(index + count, item);     }     listView.EndUpdate();   }   listView.Focus(); }