asp.net下载的几种常用的方式

asp.net下载的几种常用的方式如下。在下载的时候，为了防止弹出窗口，可以采用在原页面加一个

<iframe id="iDownload" style="display:none;" ></iframe> 

然后用jquery语句指定下载链接。

$("#iDownload").attr("src", "download.ashx?filename=" + encodeURI($(this).children("span").first().text()));

 

protected void Button1_Click(object sender, EventArgs e) 
  { 
  /* 
  微软为Response对象提供了一个新的方法TransmitFile来解决使用Response.BinaryWrite 
  下载超过400mb的文件时导致Aspnet_wp.exe进程回收而无法成功下载的问题。 
  代码如下： 
  */ 
  Response.ContentType = "application/x-zip-compressed"; 
  Response.AddHeader("Content-Disposition", "attachment;filename=z.zip"); 
  string filename = Server.MapPath("DownLoad/aaa.zip"); 
  Response.TransmitFile(filename); 
  }


  //WriteFile实现下载 
  protected void Button2_Click(object sender, EventArgs e) 
  { 
  /* 
  using System.IO; 
  */ 
  string fileName ="aaa.zip";//客户端保存的文件名 
  string filePath=Server.MapPath("DownLoad/aaa.zip");//路径 
  FileInfo fileInfo = new FileInfo(filePath); 
  Response.Clear(); 
  Response.ClearContent(); 
  Response.ClearHeaders(); 
  Response.AddHeader("Content-Disposition", "attachment;filename=" + fileName); 
  Response.AddHeader("Content-Length", fileInfo.Length.ToString()); 
  Response.AddHeader("Content-Transfer-Encoding", "binary"); 
  Response.ContentType = "application/octet-stream"; 
  Response.ContentEncoding = System.Text.Encoding.GetEncoding("gb2312"); 
  Response.WriteFile(fileInfo.FullName); 
  Response.Flush(); 
  Response.End(); 
  }


  //WriteFile分块下载 
  protected void Button3_Click(object sender, EventArgs e) 
  { 
  string fileName = "aaa.zip";//客户端保存的文件名 
  string filePath = Server.MapPath("DownLoad/aaa.zip");//路径 
  System.IO.FileInfo fileInfo = new System.IO.FileInfo(filePath); 
  if (fileInfo.Exists == true) 
  { 
  const long ChunkSize = 102400;//100K 每次读取文件，只读取100Ｋ，这样可以缓解服务器的压力 
  byte[] buffer = new byte[ChunkSize]; 
  Response.Clear(); 
  System.IO.FileStream iStream = System.IO.File.OpenRead(filePath); 
  long dataLengthToRead = iStream.Length;//获取下载的文件总大小 
  Response.ContentType = "application/octet-stream"; 
  Response.AddHeader("Content-Disposition", "attachment; filename=" + HttpUtility.UrlEncode(fileName)); 
  while (dataLengthToRead &gt; 0 && Response.IsClientConnected)  
  { 
  int lengthRead = iStream.Read(buffer, 0, Convert.ToInt32(ChunkSize));//读取的大小 
  Response.OutputStream.Write(buffer, 0, lengthRead); 
  Response.Flush(); 
  dataLengthToRead = dataLengthToRead - lengthRead; 
  } 
  Response.Close(); 
  } 
  }


  //流方式下载 
  protected void Button4_Click(object sender, EventArgs e) 
  { 
  string fileName = "aaa.zip";//客户端保存的文件名 
  string filePath = Server.MapPath("DownLoad/aaa.zip");//路径 
  //以字符流的形式下载文件 
  FileStream fs = new FileStream(filePath, FileMode.Open); 
  byte[] bytes = new byte[(int)fs.Length]; 
  fs.Read(bytes, 0, bytes.Length); 
  fs.Close(); 
  Response.ContentType = "application/octet-stream"; 
  //通知浏览器下载文件而不是打开 
  Response.AddHeader("Content-Disposition", "attachment; filename=" + HttpUtility.UrlEncode(fileName, System.Text.Encoding.UTF8)); 
  Response.BinaryWrite(bytes); 
  Response.Flush(); 
  Response.End(); 
  }