asp.net中Exce文件下载

先试用Response.WriteFile的方法：

FileInfo fi = new FileInfo(excelFile);//excelFile为文件在服务器上的地址
HttpResponse contextResponse = HttpContext.Current.Response;
contextResponse.Clear();
contextResponse.Buffer = true;
contextResponse.Charset = "GB2312"; //设置了类型为中文防止乱码的出现 
contextResponse.AppendHeader("Content-Disposition", String.Format("attachment;filename={0}", excelName)); //定义输出文件和文件名 
contextResponse.AppendHeader("Content-Length", fi.Length.ToString());
contextResponse.ContentEncoding = Encoding.Default;
contextResponse.ContentType = "application/ms-excel";//设置输出文件类型为excel文件。 

contextResponse.WriteFile(fi.FullName);
contextResponse.Flush();
contextResponse.End();

分段下载：

    private bool DownFile(HttpResponse response,string filename,string fullpath)
    {
        try
        {
            response.ContentType = "application/octet-stream";//"application/octet-stream";
            response.AppendHeader("content-disposition", "attachment;filename=" +
            System.Web.HttpUtility.UrlEncode(filename, System.Text.Encoding.UTF8) + ";charset=gb2312");
            System.IO.FileStream fs = System.IO.File.OpenRead(fullpath);
            long flen = fs.Length;
            int size = 102400;//每100k同时下载数据 
            byte[] readdata = new byte[size];//指定缓冲区的大小 
            if (size > flen) size = Convert.ToInt32(flen);
            long fpos = 0;
            bool isend = false;
            while (!isend)
            {
                if ((fpos + size) >= flen)
                {
                    size = Convert.ToInt32(flen - fpos);
                    readdata = new byte[size];
                    isend = true;
                }
                fs.Read(readdata, 0, size);//读入一个压缩块 
                response.BinaryWrite(readdata);
                fpos += size;
            }
            fs.Close();
            return true;
        }
        catch
        {
            return false;
        }
    }