Asp.net(c#)实现多线程断点续传

asp教程.net(c#)实现多线程断点续传

stream istream = null;
byte[] buffer = new byte[10240];// 缓冲区块10k bytes :
int length;
long datatoread;
string filepath = @"e:softwaresql server 2000 personal edition.iso";
string filename = system.io.path.getfilename(filepath);
try
{
// 打开文件 istream = new filestream(filepath, filemode.open,fileaccess.read, fileshare.read);
response.clear();
datatoread = istream.length;
long p = 0;
if (request.headers["range"] != null)
{
response.statuscode = 206;
p = long.parse(request.headers["range"].replace("bytes=", "").replace("-", ""));
}
if (p != 0)
{
response.addheader("content-range", "bytes " + p.tostring() + "-" + ((long)(datatoread - 1)).tostring() + "/" + datatoread.tostring());
}
response.addheader("content-length", ((long)(datatoread - p)).tostring());
response.contenttype = "application/octet-stream";
response.addheader("content-disposition", "attachment; filename=" + system.web.httputility.urlencode(request.contentencoding.getbytes(filename)));

istream.position = p;
datatoread = datatoread - p;
while (datatoread > 0)
{
if (response.isclientconnected)
{
length = istream.read(buffer, 0, 10240);
response.outputstream.write(buffer, 0, length);
response.flush();

buffer = new byte[10240];
datatoread = datatoread - length;
}
else
{
//如果用户断开连接 防止无限循环 datatoread = -1;
}
}
}
catch (exception ex)
{
response.write("error : " + ex.message);
}
finally
{
if (istream != null)
{
istream.close();
}
response.end();
}
}