asp.net下载文件方法
/*
* 输入参数
* _Request: Page.Request 对象
* _Response: Page.Response 对象
* _fileName: 下载文件名
* _fullPath: 带文件名下载路径
* _speed 每秒允许下载的字节数
* 返回是否成功
*/
public static bool ResponseFile(HttpRequest _Request,HttpResponse _Response,string _fileName,string _fullPath, long _speed) {
try {
FileStream myFile = new FileStream(_fullPath, FileMode.Open, FileAccess.Read, FileShare.ReadWrite);
BinaryReader br = new BinaryReader(myFile);
try {
_Response.AddHeader("Accept-Ranges", "bytes");
_Response.Buffer = false;
long fileLength = myFile.Length;
long startBytes = 0;
int pack = 10240; //10K bytes
//int sleep = 200; //每秒5次 即5*10K bytes每秒
int sleep = (int)Math.Floor(1000 * pack / _speed) + 1;
if (_Request.Headers["Range"] != null) {
_Response.StatusCode = 206;
string[] range = _Request.Headers["Range"].Split(new char[] {@#=@#, @#-@#});
startBytes = Convert.ToInt64(range[1]);
}
_Response.AddHeader("Content-Length", (fileLength - startBytes).ToString());
if (startBytes != 0) {
_Response.AddHeader("Content-Range", string.Format(" bytes {0}-{1}/{2}", startBytes, fileLength-1, fileLength));
}
_Response.AddHeader("Connection", "Keep-Alive");
_Response.ContentType = "application/octet-stream";
_Response.AddHeader("Content-Disposition","attachment;filename=" + HttpUtility.UrlEncode(_fileName,System.Text.Encoding.UTF8) );
br.BaseStream.Seek(startBytes, SeekOrigin.Begin);
int maxCount = (int) Math.Floor((fileLength - startBytes) / pack) + 1;
for (int i = 0;i < maxCount;i++) {
if (_Response.IsClientConnected) {
_Response.BinaryWrite(br.ReadBytes(pack));
Thread.Sleep(sleep);
}else {
i=maxCount;
}
}
}catch {
return false;
}finally {
br.Close();
myFile.Close();
}
}catch {
return false;
}
return true;
}
调用例
Page.Response.Clear(); bool success = ResponseFile(Page.Request, Page.Response, "filename", @"C:\download.date", 1024000); if(!success) Response.Write("下载文件出错！"); Page.Response.End();如何通过ASP.NET来下载文件，这个问题我们经常遇到，把常用的方法总结到一起，学习学习。当我们要让用户下载一个文件，最简单的方式是通过Response.Redirect指令：Response.Redirect("test.doc")
您可以把上面这行指令放在Button的Click事件当中，当用户点击按钮之后，网页就会被转址到该word档，造成下载的效果。但是这样的下载有几个问题：
1、无法下载不存在的文件：例如，我们若是想把程序动态(临时)产生的文字，当作一个文件下载的时候(也就是该文件其实原先并不是真的存在，而是动态产生的)，就无法下载。
2、无法下载存储于数据库中的文件：这是类似的问题，该文件并没有真的存在，只是被存放在数据库中的某个位置(某笔记录中的某个栏位)的时候，就无法下载。
3、无法下载不存在于Web文件夹中的文件：文件确实存在，但该文件夹并不是可以分享出来的Web文件夹，例如，该文件的位置在C:\winnt，您总不会想要把该文件夹当作Web文件夹吧?这时候，由于您无法使用Redirect指向该位置，所以无法下载。
4、下载文件后，原本的页面将会消失。
典型的状况是，我们要让用户下载一个.txt文件或是.csv格式的Excel文件，但是...
1、这个文件可能是通过ASP.NET程序动态产生的，而不是确实存在于Server端的文件；
2、或是它虽然存在于伺服器端的某个实体位置，但我们并不想暴露这个位置(如果这个位置公开，很可能没有权限的用户也可以在网址栏上输入URL直接取得!!!)
3、或是这个位置并不在网站虚拟路径所在的文件夹中。(例如C:\Windows\System32...)
//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();
}
//----------------------------------------------------------
public void DownloadFile( System.Web.UI.Page WebForm,String FileNameWhenUserDownload ,String FileBody ){
WebForm.Response.ClearHeaders();
WebForm.Response.Clear();
WebForm.Response.Expires = 0;
WebForm.Response.Buffer = true;
WebForm.Response.AddHeader("Accept-Language", "zh-tw");
//\'文件名称
WebForm.Response.AddHeader("content-disposition", "attachment; filename=\'"+System.Web.HttpUtility.UrlEncode(FileNameWhenUserDownload, System.Text.Encoding.UTF8)+"\'");
WebForm.Response.ContentType = "Application/octet-stream";
//\'文件内容
WebForm.Response.Write(FileBody);//-----------
WebForm.Response.End();
}
//上面这段代码是下载一个动态产生的文本文件，若这个文件已经存在于服务器端的实体路径，则可以通过下面的函数：
public void DownloadFileByFilePath( System.Web.UI.Page WebForm,String FileNameWhenUserDownload ,String FilePath )
{
WebForm.Response.ClearHeaders();
WebForm.Response.Clear();
WebForm.Response.Expires = 0;
WebForm.Response.Buffer = true;
WebForm.Response.AddHeader("Accept-Language", "zh-tw");
//文件名称
WebForm.Response.AddHeader("content-disposition", "attachment; filename=\'" + System.Web.HttpUtility.UrlEncode(FileNameWhenUserDownload, System.Text.Encoding.UTF8) +"\'" );
WebForm.Response.ContentType = "Application/octet-stream";
//文件内容
WebForm.Response.Write(System.IO.File.ReadAllBytes(FilePath));//---------
WebForm.Response.End();
}
下面是更详细的ContentType
\'ez\' => \'application/andrew-inset\',
\'hqx\' => \'application/mac-binhex40\',
\'cpt\' => \'application/mac-compactpro\',
\'doc\' => \'application/msword\',
\'bin\' => \'application/octet-stream\',
\'dms\' => \'application/octet-stream\',
\'lha\' => \'application/octet-stream\',
\'lzh\' => \'application/octet-stream\',
\'exe\' => \'application/octet-stream\',
\'class\' => \'application/octet-stream\',
\'so\' => \'application/octet-stream\',
\'dll\' => \'application/octet-stream\',
\'oda\' => \'application/oda\',
\'pdf\' => \'application/pdf\',
\'ai\' => \'application/postscript\',
\'eps\' => \'application/postscript\',
\'ps\' => \'application/postscript\',
\'smi\' => \'application/smil\',
\'smil\' => \'application/smil\',
\'mif\' => \'application/vnd.mif\',
\'xls\' => \'application/vnd.ms-excel\',
\'ppt\' => \'application/vnd.ms-powerpoint\',
\'wbxml\' => \'application/vnd.wap.wbxml\',
\'wmlc\' => \'application/vnd.wap.wmlc\',
\'wmlsc\' => \'application/vnd.wap.wmlscriptc\',
\'bcpio\' => \'application/x-bcpio\',
\'vcd\' => \'application/x-cdlink\',
\'pgn\' => \'application/x-chess-pgn\',
\'cpio\' => \'application/x-cpio\',
\'csh\' => \'application/x-csh\',
\'dcr\' => \'application/x-director\',
\'dir\' => \'application/x-director\',
\'dxr\' => \'application/x-director\',
\'dvi\' => \'application/x-dvi\',
\'spl\' => \'application/x-futuresplash\',
\'gtar\' => \'application/x-gtar\',
\'hdf\' => \'application/x-hdf\',
\'js\' => \'application/x-javascript\',
\'skp\' => \'application/x-koan\',
\'skd\' => \'application/x-koan\',
\'skt\' => \'application/x-koan\',
\'skm\' => \'application/x-koan\',
\'latex\' => \'application/x-latex\',
\'nc\' => \'application/x-netcdf\',
\'cdf\' => \'application/x-netcdf\',
\'sh\' => \'application/x-sh\',
\'shar\' => \'application/x-shar\',
\'swf\' => \'application/x-shockwave-flash\',
\'sit\' => \'application/x-stuffit\',
\'sv4cpio\' => \'application/x-sv4cpio\',
\'sv4crc\' => \'application/x-sv4crc\',
\'tar\' => \'application/x-tar\',
\'tcl\' => \'application/x-tcl\',
\'tex\' => \'application/x-tex\',
\'texinfo\' => \'application/x-texinfo\',
\'texi\' => \'application/x-texinfo\',
\'t\' => \'application/x-troff\',
\'tr\' => \'application/x-troff\',
\'roff\' => \'application/x-troff\',
\'man\' => \'application/x-troff-man\',
\'me\' => \'application/x-troff-me\',
\'ms\' => \'application/x-troff-ms\',
\'ustar\' => \'application/x-ustar\',
\'src\' => \'application/x-wais-source\',
\'xhtml\' => \'application/xhtml+xml\',
\'xht\' => \'application/xhtml+xml\',
\'zip\' => \'application/zip\',
\'au\' => \'audio/basic\',
\'snd\' => \'audio/basic\',
\'mid\' => \'audio/midi\',
\'midi\' => \'audio/midi\',
\'kar\' => \'audio/midi\',
\'mpga\' => \'audio/mpeg\',
\'mp2\' => \'audio/mpeg\',
\'mp3\' => \'audio/mpeg\',
\'aif\' => \'audio/x-aiff\',
\'aiff\' => \'audio/x-aiff\',
\'aifc\' => \'audio/x-aiff\',
\'m3u\' => \'audio/x-mpegurl\',
\'ram\' => \'audio/x-pn-realaudio\',
\'rm\' => \'audio/x-pn-realaudio\',
\'rpm\' => \'audio/x-pn-realaudio-plugin\',
\'ra\' => \'audio/x-realaudio\',
\'wav\' => \'audio/x-wav\',
\'pdb\' => \'chemical/x-pdb\',
\'xyz\' => \'chemical/x-xyz\',
\'bmp\' => \'image/bmp\',
\'gif\' => \'image/gif\',
\'ief\' => \'image/ief\',
\'jpeg\' => \'image/jpeg\',
\'jpg\' => \'image/jpeg\',
\'jpe\' => \'image/jpeg\',
\'png\' => \'image/png\',
\'tiff\' => \'image/tiff\',
\'tif\' => \'image/tiff\',
\'djvu\' => \'image/vnd.djvu\',
\'djv\' => \'image/vnd.djvu\',
\'wbmp\' => \'image/vnd.wap.wbmp\',
\'ras\' => \'image/x-cmu-raster\',
\'pnm\' => \'image/x-portable-anymap\',
\'pbm\' => \'image/x-portable-bitmap\',
\'pgm\' => \'image/x-portable-graymap\',
\'ppm\' => \'image/x-portable-pixmap\',
\'rgb\' => \'image/x-rgb\',
\'xbm\' => \'image/x-xbitmap\',
\'xpm\' => \'image/x-xpixmap\',
\'xwd\' => \'image/x-xwindowdump\',
\'igs\' => \'model/iges\',
\'iges\' => \'model/iges\',
\'msh\' => \'model/mesh\',
\'mesh\' => \'model/mesh\',
\'silo\' => \'model/mesh\',
\'wrl\' => \'model/vrml\',
\'vrml\' => \'model/vrml\',
\'css\' => \'text/css\',
\'html\' => \'text/html\',
\'htm\' => \'text/html\',
\'asc\' => \'text/plain\',
\'txt\' => \'text/plain\',
\'rtx\' => \'text/richtext\',
\'rtf\' => \'text/rtf\',
\'sgml\' => \'text/sgml\',
\'sgm\' => \'text/sgml\',
\'tsv\' => \'text/tab-separated-values\',
\'wml\' => \'text/vnd.wap.wml\',
\'wmls\' => \'text/vnd.wap.wmlscript\',
\'etx\' => \'text/x-setext\',
\'xsl\' => \'text/xml\',
\'xml\' => \'text/xml\',
\'mpeg\' => \'video/mpeg\',
\'mpg\' => \'video/mpeg\',
\'mpe\' => \'video/mpeg\',
\'qt\' => \'video/quicktime\',
\'mov\' => \'video/quicktime\',
\'mxu\' => \'video/vnd.mpegurl\',
\'avi\' => \'video/x-msvideo\',
\'movie\' => \'video/x-sgi-movie\',
\'ice\' => \'x-conference/x-cooltalk\'
转载: http://www.cnblogs.com/kingkoo/archive/2009/08/08/1541593.html