Use ftp to upload and download files-C #

// FTP File Upload, filename: file to be uploaded, filenewname: name to be saved on the server
Private void upload (string filename, string filenewname)
{
String strfilename = "";

// Obtain information about the object
Fileinfo fileinf = new fileinfo (filename );
If (filenewname = "")
{
Strfilename = fileinf. Name;
}
Else
{
Strfilename = filenewname;
}

// Create an ftpwebrequest object based on the URI
Ftpwebrequest reqftp;
Reqftp = (ftpwebrequest) ftpwebrequest. Create (New uri ("ftp: // 127.0.0.1/" + strfilename ));

// FTP user name and password
Reqftp. Credentials = new networkcredential ("yans1", "123456 ");

// Destroy the connection to the server
Reqftp. keepalive = true;
// Obtain or set the command to be sent to the FTP server.
Reqftp. method = webrequestmethods. FTP. uploadfile;
// The data format of the transmitted file is binary.
Reqftp. usebinary = true;
// File Size
Reqftp. contentlength = fileinf. length;

// Set the buffer size to 2 kb.
Int bufflength = 2048;
Byte [] buff = new byte [bufflength];
Int contentlen;

Try
{
Stream STRM = reqftp. getrequeststream ();

// Read the file into the stream
Filestream FS = fileinf. openread ();
// Stores the data sent from the current request to the server.
// Package the file stream into a small byte array to prevent occupying too much Server Memory
Contentlen = FS. Read (buff, 0, bufflength );
// Cyclically write the file stream into the request stream to be sent to the FTP server
While (contentlen! = 0)
{
STRM. Write (buff, 0, contentlen );
Contentlen = FS. Read (buff, 0, bufflength );
}

FS. Close ();
STRM. Close ();
}
Catch (exception E)
{
Response. Write (E. Message. tostring ());
}
}

// FTP File Download, filepath: local path, filename: name of the file to be downloaded
Private void download (string filepath, string filename)
{
// Declare the request
Ftpwebrequest reqftp;
Reqftp = (ftpwebrequest) ftpwebrequest. Create (New uri ("ftp: // 127.0.0.1/" + filename ));

// Destroy the connection to the server
Reqftp. keepalive = true;
// Set the command form to be sent
Reqftp. method = webrequestmethods. FTP. downloadfile;
// Set the file to be passed in binary format
Reqftp. usebinary = true;
// Set the login user name and password
Reqftp. Credentials = new networkcredential ("yans1", "123456 ");
// Try
//{
// Obtain the FTP Response
Ftpwebresponse response = (ftpwebresponse) reqftp. getresponse ();
Stream ftpstream = response. getresponsestream ();

// Create a local save file stream
Filestream outputstream = new filestream (filepath + "/" + filename, filemode. Create );

Int buffer size = 2048;
Int readcount;
Byte [] buffer = new byte [buffersize];

readcount = ftpstream. read (buffer, 0, buffersize);
while (readcount> 0)
{< br> outputstream. write (buffer, 0, readcount);
readcount = ftpstream. read (buffer, 0, buffersize);
}

Outputstream. Close ();
Ftpstream. Close ();
Response. Close ();
//}
// Catch (exception E)
//{
// Response. Write (E. Message. tostring ());
//}

}

// Obtain the list of all files in the FTP directory
Private string [] getfilelist ()
{
Stringbuilder result = new stringbuilder ();

// Create a request
Ftpwebrequest reqftp;
Reqftp = (ftpwebrequest) ftpwebrequest. Create (New uri ("ftp: // 127.0.0.1" + "/"));

// Set Request attributes
Reqftp. keepalive = true;
Reqftp. method = webrequestmethods. FTP. listdirectory;
Reqftp. usebinary = true;

// Set the user and password
Reqftp. Credentials = new networkcredential ("yans1", "123456 ");
Ftpwebresponse resftp = (ftpwebresponse) reqftp. getresponse ();

// obtain the response stream
streamreader READ = new streamreader (resftp. getresponsestream ();

string line = read. Readline ();
while (line! = NULL & line! = "")
{// determines whether the file is a file or a file
result. append (line);
result. append (char) 1);
line = read. readline ();
}< br> // remove the last character
result. remove (result. tostring (). lastindexof (char) 1), 1);
Read. close ();
resftp. close ();
return result. tostring (). split (char) 1);
}