private void Form1_DragDrop(object sender, DragEventArgs e)
        {
            string path = ((System.Array)e.Data.GetData(DataFormats.FileDrop)).GetValue(0).ToString();
            listBox1.Items.Add(path);//ᅬᅯᅧ홰ᅣᄐ탸ᅡᄐ
        }
private void Form1_DragEnter(object sender, DragEventArgs e)
        {
            if (e.Data.GetDataPresent(DataFormats.FileDrop))
                e.Effect = DragDropEffects.Link;
            else
               e.Effect = DragDropEffects.None;
        }
private void button1_Click(object sender, EventArgs e)
        {
            if (listBox1.Items.Count == 0)
            {
                MessageBox.Show("no file name ");
            }
            else
            {
                func_SearchFiles(sender, e);//取得文件名
            }
        }