Principle and code of c # connecting to ftp for upload/download

Copy codeThe Code is as follows:
Using System;
Using System. Collections. Generic;
Using System. Text;
Using System. Net;
Using System. IO;
Namespace ftponload
{
Class Program
{
Static void Main (string [] args)
{
// File Upload Method
Onload ("D: // outPut.txt ");
// Method for downloading an object
Fload ();
}
Public static void onload (string file)
{
// Construct a web server request object
FtpWebRequest ftp;
// Instantiate a file object
FileInfo f = new FileInfo (file );
Ftp = (FtpWebRequest) FtpWebRequest. Create (new Uri ("ftp: // 192.168.0.150/" + f. Name ));
// Create a user name and password
Ftp. Credentials = new NetworkCredential ("123", "123 ");
Ftp. KeepAlive = false;
Ftp. Method = WebRequestMethods. Ftp. UploadFile;
Ftp. UseBinary = true;
Ftp. ContentLength = f. Length;
Int buffLength = 20480;
Byte [] buff = new byte [buffLength];
Int contentLen;
Try
{
// Obtain the input stream of the request object
FileStream fs = f. OpenRead ();
Stream sw = ftp. GetRequestStream ();
ContentLen = fs. Read (buff, 0, buffLength );
While (contentLen! = 0)
{
Sw. Write (buff, 0, contentLen );
ContentLen = fs. Read (buff, 0, buffLength );
}
Sw. Close ();
Fs. Close ();
}
Catch (Exception e)
{
Console. WriteLine (e. Message );
}
}
Public static void fload ()
{
FtpWebRequest ftp;
Ftp = (FtpWebRequest) FtpWebRequest. Create (new Uri ("ftp: // 192.168.0.6/connect to the file you specified "));
// Specify the user name and password
Ftp. Credentials = new NetworkCredential ("123", "123456 ");
WebResponse wr = ftp. GetResponse ();
StreamReader sr = new StreamReader (wr. GetResponseStream (), System. Text. Encoding. Default );
String s = sr. ReadLine ();
While (s. Equals (""))
{
S = sr. ReadLine ();
}
}
}
}