C#下载功能代码

 

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)

 {

 /*

 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/z.zip");

 Response.TransmitFile(filename);

 }



 //WriteFile实现下载

 protected void Button2_Click(object sender, EventArgs e)

 {

 /*

 using System.IO;



 */



 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();



 }

}

 使用GridView等控件导出Excel

 

public void outExcel()

        {

            string name = returnName();



            string style = @"<style>.text{mso-number-format:\@;}</style>";



            Response.ClearContent();



            Response.Buffer = true;

            Response.Charset = "gb2312";

            Response.ContentEncoding = System.Text.Encoding.GetEncoding("GB2312");



            Response.AddHeader("content-disposition", "attachment; filename=" + System.Web.HttpUtility.UrlEncode(name, System.Text.Encoding.UTF8) + ".xls");



            Response.ContentType = "application/excel";



            StringWriter sw = new StringWriter();



            HtmlTextWriter htw = new HtmlTextWriter(sw);



            GridView1.RenderControl(htw);



            Response.Write(style);



            Response.Write(sw.ToString());



            Response.End();

        }