C3 WinApp อยากลากไฟล์มาลงใน DataGridView แล้วให้ดึงชื่อไฟล์มาครับ

 private void table1DataGridView_DragDrop(object sender, DragEventArgs e)
        {
            string cellvalue = e.Data.GetData(typeof(string)) as string;
            Point cursorLocation = this.PointToClient(new Point(e.X, e.Y));

            System.Windows.Forms.DataGridView.HitTestInfo hittest = table1DataGridView.HitTest(cursorLocation.X, cursorLocation.Y);
            if (hittest.ColumnIndex != -1
                && hittest.RowIndex != -1)
                table1DataGridView[hittest.ColumnIndex, hittest.RowIndex].Value = cellvalue;
        }

        private void table1DataGridView_DragEnter(object sender, DragEventArgs e)
        {
            e.Effect = DragDropEffects.Copy;
        }

        private void table1DataGridView_MouseMove(object sender, MouseEventArgs e)
        {
            if (e.Button == MouseButtons.Left)
            {
                DataGridView.HitTestInfo info = table1DataGridView.HitTest(e.X, e.Y);
                if (info.RowIndex >= 0)
                {
                    if (info.RowIndex >= 0 && info.ColumnIndex >= 0)
                    {
                        string text = (String)table1DataGridView.Rows[info.RowIndex].Cells[info.ColumnIndex].Value;
                        if (text != null)
                            table1DataGridView.DoDragDrop(text, DragDropEffects.Copy);
                    }
                }
            }
        }