欢迎您访问程序员文章站本站旨在为大家提供分享程序员计算机编程知识!
您现在的位置是: 首页  >  IT编程

ASP.NET中下载文件的几种实例代码

程序员文章站 2024-03-04 18:37:48
复制代码 代码如下:  //transmitfile实现下载     protected void button1_click(ob...

复制代码 代码如下:

  //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();
}
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

--保存文档
string docname, docextended;
stream doc = fudoc.filecontent;
int doclength = fudoc.postedfile.contentlength;
byte[] docdata = new byte[doclength];
doc.read(docdata, 0, doclength);
docextended = fudoc.filename.substring(fudoc.filename.indexof("."));
if (string.isnullorempty(tbdoc.text))
docname = fudoc.filename;
else
docname = tbdoc.text + docextended;
safetydocinfo data = new safetydocinfo(ddlsort.text, docname, fudoc.postedfile.contenttype, docdata);
safetydoc safety = new safetydoc();
safety.insert(data);
tbdoc.text = string.empty;
--打开文档
public void viewsafetydoc(string pdocsort, string pdocname)
{
oracleparameter[] parms = getsafetydocparm(sql_view_safetydoc);
parms[0].value = pdocsort;
parms[1].value = pdocname;
using (oracledatareader rdr = oraclehelper.executereader(oraclehelper.connectionstring, commandtype.text, sql_view_safetydoc, parms))
{
while (rdr.read())
{
httpcontext.current.response.clear();
httpcontext.current.response.buffer = true;
httpcontext.current.response.charset = "gb2312";
httpcontext.current.response.contentencoding = system.text.encoding.getencoding("gb2312");
httpcontext.current.response.contenttype = rdr.getstring(1);
httpcontext.current.response.binarywrite((byte[])rdr["doc"]);
string filename = rdr.getstring(0);
filename = system.web.httputility.urlencode(filename, system.text.encoding.utf8);
httpcontext.current.response.appendheader("content-disposition", "attachment;filename=" + filename);
}
}
}