private void textBox1_DragDrop(object sender, DragEventArgs e)        {            textBox1.Text = ((System.Array)e.Data.GetData(DataFormats.FileDrop)).GetValue(0).ToString();        }        private void textBox1_DragEnter(object sender, DragEventArgs e)        {            if (e.Data .GetDataPresent(DataFormats .FileDrop ))            {                e.Effect = DragDropEffects.Link;            }            else            {                e.Effect = DragDropEffects.None;            }        }