c#下载文件的疑问 谢谢

Question

在浏览器上点击“下载”按钮，就将服务器的一个文件下载到本地，保存成.txt形式，该怎么保存成.txt形式，并让用户选择保存路径？
谢谢

Answer 1

protected void Button1_Click( object sender, System.EventArgs e )
  {
    Response.Clear();
    Response.Buffer = true;
    Response.AppendHeader("Content-Disposition", "attachment;filename=FileName.txt");
    Response.WriteFile("xxxxx.txt");
    Response.Flush();
    Response.End();  }

Answer 2

string fileName = "";//客户端保存的文件名
            string filePath = Server.MapPath("");//路径            FileInfo fileInfo = new FileInfo(filePath);
            Response.Clear();
            Response.ClearContent();
            Response.ClearHeaders();
            Response.AddHeader("Content-Disposition", "attachment;filename=" + fileName);
            Response.AddHeader("Content-Length", fileInfo.Length.ToString());
            Response.AddHeader("Content-Transfer-Encoding", "binary");
            Response.ContentType = "application/octet-stream";
            Response.ContentEncoding = System.Text.Encoding.GetEncoding("gb2312");
            Response.WriteFile(fileInfo.FullName);
            Response.Flush();
            Response.End();
 //字符流方式下载文件
        protected void Button4_Click(object sender, EventArgs e)
        {
            string fileName = "";//客户端保存的文件名
            string filePath = Server.MapPath("");//路径            //以字符流的形式下载文件
            FileStream fs = new FileStream(filePath, FileMode.Open);
            byte[] bytes = new byte[(int)fs.Length];
            fs.Read(bytes, 0, bytes.Length);
            fs.Close();
            Response.ContentType = "application/octet-stream";
            Response.AddHeader("Content-Disposition", "attachment;   filename=" + HttpUtility.UrlEncode(fileName, System.Text.Encoding.UTF8));
            Response.BinaryWrite(bytes);
            Response.Flush();
            Response.End();
        }