C# 文件下载四方法

C# code

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;

publicpartialclass _Default : System.Web.UI.Page

{

protectedvoid Page_Load(object sender, EventArgs e) { }

//TransmitFile实现下载

protectedvoid 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

protectedvoid 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

protectedvoid 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)

{

constlong 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 =newbyte[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

protectedvoid 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 =newbyte[(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();

}

}