C#實現文件下載

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實現下載
protected void Button1_Click(object sender, EventArgs e)
{
/* 微軟爲Response對象提供了一個新的方法TransmitFile來解決使用Response.BinaryWrite 下載超過400mb的文件時導致Aspnet_wp.exe進程回收而無法成功下載的問題。 代碼如下： */
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實現下載
protected void Button2_Click(object sender, EventArgs e)
{
/* using System.IO; */
string fileName = "asd.txt";//客戶端保存的文件名
string filePath = Server.MapPath("DownLoad/aaa.txt");//路徑
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分塊下載
protected void Button3_Click(object sender, EventArgs e)
{
string fileName = "aaa.txt";//客戶端保存的文件名
string filePath = Server.MapPath("DownLoad/aaa.txt");//路徑
System.IO.FileInfo fileInfo = new System.IO.FileInfo(filePath);
if (fileInfo.Exists == true)
{
const long ChunkSize = 102400;//100K 每次讀取文件，只讀取100K，這樣可以緩解服務器的壓力
byte[] buffer = new byte[ChunkSize];
Response.Clear();
System.IO.FileStream iStream = System.IO.File.OpenRead(filePath);
long dataLengthToRead = iStream.Length;//獲取下載的文件總大小
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));//讀取的大小 Response.OutputStream.Write(buffer, 0, lengthRead);
Response.Flush();
dataLengthToRead = dataLengthToRead - lengthRead;
}
Response.Close();
}
}
//流方式下載
protected void Button4_Click(object sender, EventArgs e)
{
string fileName = "aaa.txt";//客戶端保存的文件名
string filePath = Server.MapPath("DownLoad/aaa.txt");//路徑 //以字符流的形式下載文件
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"; //通知瀏覽器下載文件而不是打開 Response.AddHeader("Content-Disposition", "attachment; filename=" + HttpUtility.UrlEncode(fileName, System.Text.Encoding.UTF8));
Response.BinaryWrite(bytes);
Response.Flush();
Response.End();
}
}

 

詳細出處參考：http://www.jb51.net/article/21164.htm