C#窗體實現文件拖拽功能

private void textBox1_DragEnter(object sender, DragEventArgs e)
        {
            //獲得數據格式
            File.WriteAllLines("C:\\1.text", e.Data.GetFormats());
            
           
            //獲得文件名
            string[] filename = (string[])e.Data.GetData("FileNameW",true);
            textBox1.Text = filename[0];

            string entesion = Path.GetFileName(textBox1.Text);

            if (!File.Exists(textBox1.Text.Trim())) { return; }
            //讀取文件流
            using (FileStream fsOpen = File.OpenRead(textBox1.Text.Trim()))
            {
                using (FileStream fs = new FileStream("C:\\" + entesion, FileMode.Create, FileAccess.Write))
                {
                    byte[] buffer = new byte[1024 * 1024];
                    while (true)
                    {
                        int result = fsOpen.Read(buffer, 0, buffer.Length);
                        if (result <= 0)
                        {
                            break;
                        }
                        else
                        {
                            fs.Write(buffer, 0, result);
                        }
                    }
                    fs.Flush();
                }
            }

        }