C#实现下载Demo

  1 using System;
  2 using System.Data;
  3 using System.Configuration;
  4 using System.Web;
  5 using System.Web.Security;
  6 using System.Web.UI;
  7 using System.Web.UI.WebControls;
  8 using System.Web.UI.WebControls.WebParts;
  9 using System.Web.UI.HtmlControls;
 10 using System.IO;
 11 
 12 public partial class _Default : System.Web.UI.Page
 13 {
 14     protected void Page_Load(object sender, EventArgs e)
 15     {
 16 
 17     }
 18 
 19     //TransmitFile实现下载
 20     protected void Button1_Click(object sender, EventArgs e)
 21     {
 22        
 23 
 24         Response.ContentType = "application/x-zip-compressed";
 25         Response.AddHeader("Content-Disposition", "attachment;filename=z.zip");
 26         string filename = Server.MapPath("DownLoad/z.zip");
 27         Response.TransmitFile(filename);
 28     }
 29 
 30     //WriteFile实现下载
 31     protected void Button2_Click(object sender, EventArgs e)
 32     {
 33        
 34 
 35         string fileName ="asd.txt";//客户端保存的文件名
 36         string filePath=Server.MapPath("DownLoad/aaa.txt");//路径
 37 
 38         FileInfo fileInfo = new FileInfo(filePath);
 39         Response.Clear();
 40         Response.ClearContent();
 41         Response.ClearHeaders();
 42         Response.AddHeader("Content-Disposition", "attachment;filename=" + fileName);
 43         Response.AddHeader("Content-Length", fileInfo.Length.ToString());
 44         Response.AddHeader("Content-Transfer-Encoding", "binary");
 45         Response.ContentType = "application/octet-stream";
 46         Response.ContentEncoding = System.Text.Encoding.GetEncoding("gb2312");
 47         Response.WriteFile(fileInfo.FullName);
 48         Response.Flush();
 49         Response.End();
 50     }
 51 
 52     //WriteFile分块下载
 53     protected void Button3_Click(object sender, EventArgs e)
 54     {
 55 
 56         string fileName = "aaa.txt";//客户端保存的文件名
 57         string filePath = Server.MapPath("DownLoad/aaa.txt");//路径
 58 
 59         System.IO.FileInfo fileInfo = new System.IO.FileInfo(filePath);
 60 
 61         if (fileInfo.Exists == true)
 62         {
 63             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
 64             byte[] buffer = new byte[ChunkSize];
 65 
 66             Response.Clear();
 67             System.IO.FileStream iStream = System.IO.File.OpenRead(filePath);
 68             long dataLengthToRead = iStream.Length;//获取下载的文件总大小
 69             Response.ContentType = "application/octet-stream";
 70             Response.AddHeader("Content-Disposition", "attachment; filename=" + HttpUtility.UrlEncode(fileName));
 71             while (dataLengthToRead > 0 && Response.IsClientConnected)
 72             {
 73                 int lengthRead = iStream.Read(buffer, 0, Convert.ToInt32(ChunkSize));//读取的大小
 74                 Response.OutputStream.Write(buffer, 0, lengthRead);
 75                 Response.Flush();
 76                 dataLengthToRead = dataLengthToRead - lengthRead;
 77             }
 78             Response.Close();
 79         }
 80     }
 81 
 82     //流方式下载
 83     protected void Button4_Click(object sender, EventArgs e)
 84     {
 85         string fileName = "aaa.txt";//客户端保存的文件名
 86         string filePath = Server.MapPath("DownLoad/aaa.txt");//路径
 87 
 88         //以字符流的形式下载文件
 89         FileStream fs = new FileStream(filePath, FileMode.Open);
 90         byte[] bytes = new byte[(int)fs.Length];
 91         fs.Read(bytes, 0, bytes.Length);
 92         fs.Close();
 93         Response.ContentType = "application/octet-stream";
 94         //通知浏览器下载文件而不是打开
 95         Response.AddHeader("Content-Disposition", "attachment;  filename=" + HttpUtility.UrlEncode(fileName, System.Text.Encoding.UTF8));
 96         Response.BinaryWrite(bytes);
 97         Response.Flush();
 98         Response.End();
 99 
100     }
101 }