winform listView拖拽改变行顺序

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using CommonTool;

namespace WindowsFormsApp1.FrmYwzDataMainTenance
{
    public partial class FrmQuestionSort : Form
    {
        private string symptomCode;
        /// <summary>
        ///排序界面
        /// </summary>
        /// <param name="symptomCode"></param>
        public FrmQuestionSort(string symptomCode)
        {
            InitializeComponent();
            this.symptomCode = symptomCode;
        }

        private void FrmQuestionSort_Load(object sender, EventArgs e)
        {
            //填充数据
            var dic = DoDataTable.GetQuestionSortBysymptomCode(this.symptomCode);
            if (dic == null || dic.Count == 0)
            {
                MessageBox.Show("获取数据失败");
                return;
            }
            int num = 1;
            foreach (KeyValuePair<string, string> kv in dic)
            {
                string qCode = kv.Key;
                string title = kv.Value;
                string[] item = { num.ToString(), qCode, title };
                ListViewItem listViewItem = new ListViewItem(item);
                listView1.Items.Add(listViewItem);
                num++;
            }
            int width = 0;
            int columnCount = listView1.Columns.Count;
            for (int i = 0; i < columnCount - 1; i++)
                width += listView1.Columns[i].Width;
            listView1.Columns[columnCount - 1].Width = listView1.ClientSize.Width - width;
            //添加事件
            listView1.AllowDrop = true;
            listView1.ItemDrag += ListView1_ItemDrag;
            listView1.DragEnter += ListView1_DragEnter;
            listView1.DragOver += ListView1_DragOver;
            listView1.DragDrop += ListView1_DragDrop;
            listView1.DragLeave += ListView1_DragLeave;
        }

        private void ListView1_DragLeave(object sender, EventArgs e)
        {
            listView1.InsertionMark.Index = -1;
        }

        private void ListView1_DragDrop(object sender, DragEventArgs e)
        {
            int targetIndex = listView1.InsertionMark.Index;
            if (targetIndex == -1)
                return;
            if (listView1.InsertionMark.AppearsAfterItem)
                targetIndex++;

            ListViewItem draggedItem =(ListViewItem) e.Data.GetData(typeof(ListViewItem));
            listView1.BeginUpdate();
            listView1.Items.Insert(targetIndex,(ListViewItem)draggedItem.Clone());
            listView1.Items.Remove(draggedItem);
            listView1.EndUpdate();
        }

        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);

            int targetIndex = listView1.InsertionMark.NearestIndex(pt);
            if (targetIndex > -1)
            {
                Rectangle itemBounds = listView1.GetItemRect(targetIndex);
                listView1.InsertionMark.AppearsAfterItem = pt.X > itemBounds.Left + (itemBounds.Width / 2);
            }
            listView1.InsertionMark.Index = targetIndex;
        }

        private void ListView1_DragEnter(object sender, DragEventArgs e)
        {
            e.Effect = e.AllowedEffect;
        }

        private void ListView1_ItemDrag(object sender, ItemDragEventArgs e)
        {
            listView1.DoDragDrop(e.Item, DragDropEffects.Move);
        }
    }
}