文件上传下载

上传

          File.PostedFile.ContentLength //判断文件大小
          File.PostedFile.FileName  //文件名称
          File.PostedFile.ContentType  //文件类型
          Server.MapPath()  //服务器路径对应物理路径
          Directory.Exists(pathfile)  //验证文件夹是否存在
          Directory.CreateDirectory(pathfile); //创建文件夹
          url=pathfile+"1234567"+".ContentType";
          file.PostedFile.SaveAs(url);   //保存到文件夹

下载

 Response.ContentType="application/x-zip-compressed"; // 下载zip类型
        Response.AddHeader("Content-Disposition","attachment;filename=z.zip"); //以xx方式下载 attachment 附件
        string filePath =  Server.MapPath("服务器路径")  //服务器路径对应物理路径
        Response.TransmitFile(fileName); //下载

循环下载

 
        string filePath = Server.MapPath("服务器路径");
        System.IO.FileInfo fileInfo = new System.IO.FileInfo(filePath);

        if (fileInfo.Exists == true)
        {
                const long readSize = 102400;
                byte[] buffer = new byte[readSize];
                Response.Clear();
                System.IO.FileStream stram= System.IO.File.OpenRead(filePath);
                long allszie = stram.Length;//获取下载的文件总大小
                Response.ContentType = "application/octet-stream";
                Response.AddHeader("Content-Disposition", "attachment; filename=" + "filename.xx");
                while (allszie > 0 && Response.IsClientConnected)
                {
                    int lengthRead = iStream.Read(buffer, 0, Convert.ToInt32(readSize));//读取的大小
                    Response.OutputStream.Write(buffer, 0, lengthRead);
                    Response.Flush();
                    allszie = allszie - lengthRead;
                }
              Response.Close();
        }

Excel转DataSet   

string str = "Provider=Microsoft.Ace.OLEDB.12.0;" + "data source=" + savePath + ";Extended Properties='Excel 12.0; HDR=Yes; IMEX=1'";    

OleDbConnection conn= new OleDbConnection(strcon);
     try
     {
         string strsql = string.Format("SELECT * FROM  Sheet1$");
         conn.Open();
         OleDbDataAdapter command= new OleDbDataAdapter(strsql, conn);
         DataSet ds = new DataSet();
         command.Fill(ds, "[" + tableName + "$]");
         excelConn.Close();       
         return ds;