winform ListView实现拖动item

/// <summary>
        /// 当拖动某项时
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void listView1_ItemDrag(object sender, ItemDragEventArgs e)
        {          
            listView1.DoDragDrop(e.Item, DragDropEffects.Move);

        }
        /// <summary>
        /// 用鼠标拖动某项至该控件的区域时
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void listView1_DragEnter(object sender, DragEventArgs e)
        {
            e.Effect = DragDropEffects.Move;
        }

        /// <summary>
        /// 拖动时拖着某项置于某行上方时
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void listView1_DragOver(object sender, DragEventArgs e)
        {
            Point ptScreen = new Point(e.X, e.Y);
            Point pt = listView1.PointToClient(ptScreen);
            ListViewItem item = listView1.GetItemAt(pt.X, pt.Y);
            if (item != null)
                item.Selected = true;
        }

        /// <summary>
        /// 拖动结束
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void listView1_DragDrop(object sender, DragEventArgs e)
        {
            ListViewItem draggedItem = (ListViewItem)e.Data.GetData(typeof(ListViewItem));          
            Point ptScreen = new Point(e.X, e.Y);
            Point pt = listView1.PointToClient(ptScreen);
            ListViewItem TargetItem = listView1.GetItemAt(pt.X, pt.Y);//拖动的项将放置于该项之前    
            listView1.Items.Insert(TargetItem.Index, (ListViewItem)draggedItem.Clone());           
            listView1.Items.Remove(draggedItem);
        }