C# WinApp ขอแนวทางในการ DragDrop ใน DataGridView หน่อยครับ

private void dataGridView2_DragDrop(object sender, DragEventArgs e)
        {
            DataGridViewSelectedRowCollection rows = (DataGridViewSelectedRowCollection)e.Data.GetData(typeof(DataGridViewSelectedRowCollection));
            
            rowIndexFromMouseDown = dataGridView2.HitTest(e.X, e.Y).RowIndex;
            MessageBox.Show(e.X + " "+ e.Y+ " " + rowIndexFromMouseDown);
           

            for (int i = rows.Count-1; i >=0  ; i--)
            {
                if (!string.IsNullOrEmpty("" + rows[i].Cells[0].Value))
                    dataGridView2.Rows.Add(rows[i].Cells[0].Value, rows[i].Cells[1].Value, rows[i].Cells[2].Value);
            }
          /*  foreach (DataGridViewRow row in rows)
            {

                if (!string.IsNullOrEmpty("" + row.Cells[0].Value))
                dataGridView2.Rows.Add(row.Cells[0].Value, row.Cells[1].Value, row.Cells[2].Value);
               
                //dataGridView1.Rows.Remove(row);
            }*/


        }

public static int DragDropRowIndex(this System.Windows.Forms.DataGridView dgv, System.Windows.Forms.DragEventArgs e)
        {
            int r = 0;
            System.Drawing.Point p = dgv.PointToClient(new System.Drawing.Point(e.X, e.Y));
            r = dgv.HitTest(p.X, p.Y).RowIndex;
            return r;
        }

static class Program
    {
        /// <summary>
        /// The main entry point for the application.
        /// </summary>
        [STAThread]
        static void Main()
        {
            Application.EnableVisualStyles();
            Application.SetCompatibleTextRenderingDefault(false);
            Application.Run(new frmDragNDrop_2() );
        }
        public static int DragDropRowIndex(this System.Windows.Forms.DataGridView dgv, System.Windows.Forms.DragEventArgs e)
        {
            int r = 0;
            System.Drawing.Point p = dgv.PointToClient(new System.Drawing.Point(e.X, e.Y));
            r = dgv.HitTest(p.X, p.Y).RowIndex;
            return r;
        }
    }

public partial class frmDragNDrop_2 : Form
    {
        public frmDragNDrop_2()
        {
            InitializeComponent();
            this.dataGridView1.AllowDrop = true;
            this.dataGridView2.AllowDrop = true;
        }
        private int rowIndexFromMouseDown;

        private void frmDragNDrop_2_Load(object sender, EventArgs e)
        {
            for (int i = 0; i < 10; i++)
                dataGridView1.Rows.Add("Test " + i, "Tor " + i);
        }

        private void dataGridView1_MouseDown(object sender, MouseEventArgs e)
        {
            dataGridView1.DoDragDrop(dataGridView1.SelectedRows, DragDropEffects.Copy);
        }

        private void listBox2_DragDrop(object sender, System.Windows.Forms.DragEventArgs e)
        {
            DataGridViewSelectedRowCollection rows = (DataGridViewSelectedRowCollection)e.Data.GetData(typeof(DataGridViewSelectedRowCollection));
            foreach (DataGridViewRow row in rows)
            {
                try
                {
                    listBox2.Items.Add(row.Cells[1].Value);
                }
                catch { }
            }

        }

        private void listBox2_DragEnter(object sender, DragEventArgs e)
        {
           if (e.Data.GetDataPresent(typeof(DataGridViewSelectedRowCollection)))
                e.Effect = DragDropEffects.Copy;
        }

        private void dataGridView2_DragDrop(object sender, DragEventArgs e)
        {
            DataGridViewSelectedRowCollection rows = (DataGridViewSelectedRowCollection)e.Data.GetData(typeof(DataGridViewSelectedRowCollection));
            rowIndexFromMouseDown = dataGridView2.DragDropRowIndex(e);
            for (int i = rows.Count-1; i >=0  ; i--)
            {
                if (!string.IsNullOrEmpty("" + rows[i].Cells[0].Value))
                    dataGridView2.Rows.Add(rows[i].Cells[0].Value, rows[i].Cells[1].Value, rows[i].Cells[2].Value);
            }
        }

        private void dataGridView2_DragEnter(object sender, DragEventArgs e)
        {
            Text = "dataGridView2_DragEnter";
            if (e.Data.GetDataPresent(typeof(DataGridViewSelectedRowCollection))) e.Effect = DragDropEffects.Copy;
        }

        private void dataGridView2_DragOver(object sender, DragEventArgs e)
        {
            Text = "dataGridView2_DragOver";
            if (e.Data.GetDataPresent(typeof(DataGridViewSelectedRowCollection))) e.Effect = DragDropEffects.Copy;
        }

       
    }

public partial class frmDgvDragDrop : Form
    {
        public frmDgvDragDrop()
        {
            InitializeComponent();
            this.dataGridView1.AllowDrop = true;
            this.dataGridView2.AllowDrop = true;
            for (int i = 0; i < 10; i++)
                dataGridView1.Rows.Add("Test " + i, "Tor " + i);
            dataGridView1.MouseDown+=dataGridView1_MouseDown;
            dataGridView2.DragDrop += dataGridView2_DragDrop;
            dataGridView2.DragEnter+=dataGridView2_DragEnter;
        }
        private int rowIndexFromMouseDown;

        private void frmDgvDragDrop_Load(object sender, EventArgs e)
        {

        }
        private void dataGridView1_MouseDown(object sender, MouseEventArgs e)
        {

            dataGridView1.DoDragDrop(dataGridView1.SelectedRows, DragDropEffects.Copy);
        }
        private void dataGridView2_DragDrop(object sender, DragEventArgs e)
        {
            DataGridViewSelectedRowCollection rows = (DataGridViewSelectedRowCollection)e.Data.GetData(typeof(DataGridViewSelectedRowCollection));
            rowIndexFromMouseDown = dataGridView2.MouseDownRowIndex(e);
            MessageBox.Show("" + rowIndexFromMouseDown);
            for (int i = rows.Count - 1; i >= 0; i--)
            {
                if (!string.IsNullOrEmpty("" + rows[i].Cells[0].Value))
                    dataGridView2.Rows.Add(rows[i].Cells[0].Value, rows[i].Cells[1].Value, rows[i].Cells[2].Value);
            }
            e = null;
        }

        private void dataGridView2_DragEnter(object sender, DragEventArgs e)
        {
            if (e.Data.GetDataPresent(typeof(DataGridViewSelectedRowCollection))) e.Effect = DragDropEffects.Copy;
        }

    }