ASP.NETでのファイルフローの使用:Excleファイルのダウンロード、ファイルの読み取りと書き込み

  /// 

  ///     
  ///      
  /// 
  /// 
  /// 
  private void Button1_Click(object sender, System.EventArgs e)
  {
   string sFileName = Server.MapPath("./         .xls");
   FileStream fileStream=new FileStream(sFileName,FileMode.Open);
   long fileSize = fileStream.Length; 
   byte[] fileBuffer=new byte[fileSize]; 
   fileStream.Read(fileBuffer, 0, (int)fileSize); 
   //    fileStream.Close()  ，            ，       
   fileStream.Close();

   Context.Response.ContentType="application/octet-stream"; 
   Context.Response.AppendHeader("Content-Disposition","attachment;filename="+HttpUtility.UrlEncode(sFileName,Encoding.UTF8 ));
   Context.Response.AddHeader("Content-Length",fileSize.ToString()); 

   Context.Response.BinaryWrite(fileBuffer); 
   Context.Response.End(); 
   Context.Response.Close();
  }

  /// 

  ///     
  ///         
  /// 
  /// 
  /// 
  private void Button2_Click(object sender, System.EventArgs e)
  {
   string saveFileName = "         .xls";

   Response.Clear();
   Response.Buffer= true;
   //Response.Charset = "utf-8";//    ？

   //           ，             this，     ！
   //this.EnableViewState = false;
   EnableViewState = false;

   //Response.ContentType = "application/ms-excel"; //    ？
   //Response.ContentEncoding = System.Text.Encoding.UTF8;//    ？
   
   //        ，            
   //Response.AppendHeader("Content-Disposition","attachment;filename=" + saveFileName); 
   //      
   Response.AppendHeader("Content-Disposition","attachment;filename="+HttpUtility.UrlEncode(saveFileName,Encoding.UTF8 ));

   Response.WriteFile(saveFileName); 
   Response.Flush();

   Response.End();//End Close      ，   ，                  
   Response.Close();
  }

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;
 
namespace    
{
    class Program
    {
        static void Main(string[] args)
        {
            //C#      ,    FileMode.Append
            string msg = "ok";
            byte[] myByte = System.Text.Encoding.UTF8.GetBytes(msg);
            using (FileStream fsWrite = new FileStream(@"C:\1.txt", FileMode.Append))
            {
                fsWrite.Write(myByte, 0, myByte.Length);
            };
 
            //c#      
            using (FileStream fsRead = new FileStream(@"C:\1.txt", FileMode.Open))
            {
                int fsLen = (int)fsRead.Length;
                byte[] heByte = new byte[fsLen];
                int r = fsRead.Read(heByte, 0, heByte.Length);
                string myStr = System.Text.Encoding.UTF8.GetString(heByte);
                Console.WriteLine(myStr);
                Console.ReadKey();
            }
        }
    }
}