C# 文件下载四方法

C# 文件下载四方法

转自： http://www.cnblogs.com/skyshenwei/archive/2010/01/19/1651842.html
using System;
using System.Data;
using System.Configuration;
using
System.Web;
using System.Web.Security;
using System.Web.UI;
using
System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using
System.Web.UI.HtmlControls;
using System.IO;

public partial class
_Default : System.Web.UI.Page
{
protected void Page_Load(object sender,
EventArgs e)
{

}

//TransmitFile实现下载
protected void
Button1_Click(object sender, EventArgs e)
{

Response.ContentType =
"application/x-zip-compressed";
Response.AddHeader("Content-Disposition",
"attachment;filename=z.zip");
string filename =
Server.MapPath("DownLoad/z.zip");
Response.TransmitFile(filename);
}

//WriteFile实现下载
protected
void Button2_Click(object sender, EventArgs e)
{

string fileName
="asd.txt";//客户端保存的文件名
string
filePath=Server.MapPath("DownLoad/aaa.txt");//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.txt";//客户端保存的文件名
string filePath =
Server.MapPath("DownLoad/aaa.txt");//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 > 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.txt";//客户端保存的文件名
string filePath =
Server.MapPath("DownLoad/aaa.txt");//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();

}
}