asp.net 超链接 下载TEXT文件，而不是直接在IE中打开

 1 protected void Button1_Click(object sender, EventArgs e)
 2 {
 3     string sFileName = System.IO.Path.GetRandomFileName();
 4     string sGenName = "Friendly.txt";
 5 
 6     //YOu could omit these lines here as you may
 7     //not want to save the textfile to the server
 8     //I have just left them here to demonstrate that you could create the text file 
 9     using (System.IO.StreamWriter SW = new System.IO.StreamWriter(
10            Server.MapPath("TextFiles/" + sFileName + ".txt")))
11     {
12         SW.WriteLine(txtText.Text);
13         SW.Close();
14     }
15 
16     System.IO.FileStream fs = null;
17     fs = System.IO.File.Open(Server.MapPath("TextFiles/" + 
18              sFileName + ".txt"), System.IO.FileMode.Open);
19     byte[] btFile = new byte[fs.Length];
20     fs.Read(btFile, 0, Convert.ToInt32(fs.Length));
21     fs.Close();
22     Response.AddHeader("Content-disposition", "attachment; filename=" + 
23                        sGenName);
24     Response.ContentType = "application/octet-stream";
25     Response.BinaryWrite(btFile);
26     Response.End();
27 }