drag and drop from treeview to listview using C#

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;

namespace DragFromListToTree
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
            //listView1.AllowDrop = true;
            treeView1.AllowDrop = true;
        }
   
        private void listView1_ItemDrag(object sender, ItemDragEventArgs e)
        {
            listView1.DoDragDrop(e.Item, DragDropEffects.Move);

        }

        private void treeView1_DragEnter(object sender, DragEventArgs e)
        {
            // this code can be in DragOver also
            if (e.Data.GetDataPresent(typeof(ListViewItem)))
                e.Effect = DragDropEffects.Move;
        }

        private void treeView1_DragDrop(object sender, DragEventArgs e)
        {
            if (e.Data.GetDataPresent(typeof(ListViewItem)))
            {
    
                ListViewItem li = (ListViewItem)e.Data.GetData(typeof(ListViewItem));

                bool dupplicate = false;

                foreach (TreeNode tn in treeView1.Nodes)
                {
                    if (tn.Text == li.Text) dupplicate = true;
                }

                if (!dupplicate)
                {
                    treeView1.Nodes.Add(li.Text);
                    listView1.Items.Remove(li);
                }
            }
        }

    }
}