文件下载代码，可以用迅雷进行下载（因为之前用过一段下载文件的代码，但是不能用迅雷下载，超级汗！！！）

using System;
using System.Collections;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;
using System.IO;
using System.Text;
using System.Text.RegularExpressions;

namespace WEB
{
public partial class thunder : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
string filename = HttpContext.Current.Server.MapPath("//") + "//UploadFile//1.rar";
//DowenLoad(filename);
bool state = SendFile(filename);
}

private bool SendFile(string filename)
{
bool check;
try
{
Response.Clear();
Response.ClearHeaders();
FileInfo f = new FileInfo(filename);

Response.ContentType = "application/octet-stream";
Response.ContentEncoding = System.Text.Encoding.GetEncoding("gb2312");

Response.AddHeader("Content-Disposition", "attachment;filename=" + Server.UrlPathEncode(f.Name));
Response.TransmitFile(filename);

check = true;
}
catch (Exception ex)
{
check = false;
}
return check;
}

}
}