using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Linq;

using System.Text;

using System.Windows.Forms;

namespace WindowsFormsApplication4

{

    public partial class Form1 : Form

    {

        int indexofsource;//拖动的起始索引

        int indexoftarget; //拖动的结束索引

        public Form1()

        {

            InitializeComponent();

        }

        private void listBox1_MouseDown(object sender, MouseEventArgs e)

        {

            indexofsource = ((ListBox)sender).IndexFromPoint(e.X, e.Y);

            if (indexofsource != ListBox.NoMatches)

            {

                ((ListBox)sender).DoDragDrop(((ListBox)sender).Items[indexofsource].ToString(), DragDropEffects.All);

            }

        }

        private void listBox1_DragOver(object sender, DragEventArgs e)

        {

             if (e.Data.GetDataPresent(typeof(System.String)) && ((ListBox)sender).Equals(listBox1))

            {

                e.Effect = DragDropEffects.Move;

            }

            else

                e.Effect = DragDropEffects.None;

        }

        private void listBox1_DragDrop(object sender, DragEventArgs e)

        {

            ListBox listbox = (ListBox)sender;

            indexoftarget = listbox.IndexFromPoint(listbox.PointToClient(new Point(e.X, e.Y)));

            if (indexoftarget != ListBox.NoMatches)

            {

                string temp = listbox.Items[indexoftarget].ToString();

                listbox.Items[indexoftarget] = listbox.Items[indexofsource];

                listbox.Items[indexofsource] = temp;

                listbox.SelectedIndex = indexoftarget;

            }

        }

    }

}