Use response to send files to the client (ASP. NET)

Send a file to the client using response
The following is a function prototype:
Public static void responsefile (system. Web. httpserverutility Server, System. Web. httpresponse response, string filename)
{

System. Io. fileinfo file = new system. Io. fileinfo (filename );
Response. Clear ();
Response. charset = "gb2312 ";
Response. contentencoding = system. Text. encoding. utf8;
// Add the header information and specify the default file name for the "download/Save as" dialog box
Response. addheader ("content-disposition", "attachment; filename =" + server. urlencode (file. Name ));
// Add header information and specify the file size so that the browser can display the download progress.
Response. addheader ("Content-Length", file. length. tostring ());
// Specify a stream that cannot be read by the client and must be downloaded.
Response. contenttype = "application/MS-excel ";
// Send the file stream to the client
Response. writefile (file. fullname );
// Stop page execution
Response. End ();
}