Bài viết trước, mình đã có hướng dẫn các bạn sử dụng FTP server bằng VB.NET, tiếp tục bài viết này, mình xin chia sẽ cho các bạn một class library thư viện làm việc với FTP bằng C# rất đơn giản.

UPLOAD, DOWNLOAD, RENAME, CREATE DIRECTORY WITH CLASS FTP C#

Class này đã viết những hàm có sẵn: 

+ Tạo thư mục (create_directory) 

+ Upload file 

+ Download file

+ Lấy kích thước file

+ Đổi tên file...

Các bạn có thể sử dụng class mình chia sẽ để thiết kế giao diện ứng dụng như hình bên dưới:

Hướng dẫn sử dụng class thư viện FTP:

Bạn cần gọi thư viện System.IO and System.Net namespaces. Thêm class vào project, và sau đó tạo một new instance của ftp class, sử dụng function of choice, và free resource.

/* Create Object Instance */
ftp ftpClient = new ftp(@"ftp://10.10.10.10/", "user", "password");
 
/* Upload a File */
ftpClient.upload("etc/test.txt", @"C:UsersmetastructDesktop	est.txt");
 
/* Download a File */
ftpClient.download("etc/test.txt", @"C:UsersmetastructDesktop	est.txt");
 
/* Delete a File */
ftpClient.delete("etc/test.txt");
 
/* Rename a File */
ftpClient.rename("etc/test.txt", "test2.txt");
 
/* Create a New Directory */
ftpClient.createDirectory("etc/test");
 
/* Get the Date/Time a File was Created */
string fileDateTime = ftpClient.getFileCreatedDateTime("etc/test.txt");
Console.WriteLine(fileDateTime);
 
/* Get the Size of a File */
string fileSize = ftpClient.getFileSize("etc/test.txt");
Console.WriteLine(fileSize);
 
/* Get Contents of a Directory (Names Only) */
string[] simpleDirectoryListing = ftpClient.directoryListDetailed("/etc");
for (int i = 0; i < simpleDirectoryListing.Count(); i++) { Console.WriteLine(simpleDirectoryListing[i]); }
 
/* Get Contents of a Directory with Detailed File/Directory Info */
string[] detailDirectoryListing = ftpClient.directoryListDetailed("/etc");
for (int i = 0; i < detailDirectoryListing.Count(); i++) { Console.WriteLine(detailDirectoryListing[i]); }
/* Release Resources */
ftpClient = null;
Class Ftp.cs bằng C#

class ftp
{
    private string host = null;
    private string user = null;
    private string pass = null;
    private FtpWebRequest ftpRequest = null;
    private FtpWebResponse ftpResponse = null;
    private Stream ftpStream = null;
    private int bufferSize = 2048;
         
    /* Construct Object */
    public ftp(string hostIP, string userName, string password) { host = hostIP; user = userName; pass = password; }
 
    /* Download File */
    public void download(string remoteFile, string localFile)
    {
        try
        {
            /* Create an FTP Request */
            ftpRequest = (FtpWebRequest)FtpWebRequest.Create(host + "/" + remoteFile);
            /* Log in to the FTP Server with the User Name and Password Provided */
            ftpRequest.Credentials = new NetworkCredential(user, pass);
            /* When in doubt, use these options */
            ftpRequest.UseBinary = true;
            ftpRequest.UsePassive = true;
            ftpRequest.KeepAlive = true;
            /* Specify the Type of FTP Request */
            ftpRequest.Method = WebRequestMethods.Ftp.DownloadFile;
            /* Establish Return Communication with the FTP Server */
            ftpResponse = (FtpWebResponse)ftpRequest.GetResponse();
            /* Get the FTP Server's Response Stream */
            ftpStream = ftpResponse.GetResponseStream();
            /* Open a File Stream to Write the Downloaded File */
            FileStream localFileStream = new FileStream(localFile, FileMode.Create);
            /* Buffer for the Downloaded Data */
            byte[] byteBuffer = new byte[bufferSize];
            int bytesRead = ftpStream.Read(byteBuffer, 0, bufferSize);
            /* Download the File by Writing the Buffered Data Until the Transfer is Complete */
            try
            {
                while (bytesRead > 0)
                {
                    localFileStream.Write(byteBuffer, 0, bytesRead);
                    bytesRead = ftpStream.Read(byteBuffer, 0, bufferSize);
                }
            }
            catch (Exception ex) { Console.WriteLine(ex.ToString()); }
            /* Resource Cleanup */
            localFileStream.Close();
            ftpStream.Close();
            ftpResponse.Close();
            ftpRequest = null;
        }
        catch (Exception ex) { Console.WriteLine(ex.ToString()); }
        return;
    }
 
    /* Upload File */
    public void upload(string remoteFile, string localFile)
    {
        try
        {
            /* Create an FTP Request */
            ftpRequest = (FtpWebRequest)FtpWebRequest.Create(host + "/" + remoteFile);
            /* Log in to the FTP Server with the User Name and Password Provided */
            ftpRequest.Credentials = new NetworkCredential(user, pass);
            /* When in doubt, use these options */
            ftpRequest.UseBinary = true;
            ftpRequest.UsePassive = true;
            ftpRequest.KeepAlive = true;
            /* Specify the Type of FTP Request */
            ftpRequest.Method = WebRequestMethods.Ftp.UploadFile;
            /* Establish Return Communication with the FTP Server */
            ftpStream = ftpRequest.GetRequestStream();
            /* Open a File Stream to Read the File for Upload */
            FileStream localFileStream = new FileStream(localFile, FileMode.Create);
            /* Buffer for the Downloaded Data */
            byte[] byteBuffer = new byte[bufferSize];
            int bytesSent = localFileStream.Read(byteBuffer, 0, bufferSize);
            /* Upload the File by Sending the Buffered Data Until the Transfer is Complete */
            try
            {
                while (bytesSent != 0)
                {
                    ftpStream.Write(byteBuffer, 0, bytesSent);
                    bytesSent = localFileStream.Read(byteBuffer, 0, bufferSize);
                }
            }
            catch (Exception ex) { Console.WriteLine(ex.ToString()); }
            /* Resource Cleanup */
            localFileStream.Close();
            ftpStream.Close();
            ftpRequest = null;
        }
        catch (Exception ex) { Console.WriteLine(ex.ToString()); }
        return;
    }
 
    /* Delete File */
    public void delete(string deleteFile)
    {
        try
        {
            /* Create an FTP Request */
            ftpRequest = (FtpWebRequest)WebRequest.Create(host + "/" + deleteFile);
            /* Log in to the FTP Server with the User Name and Password Provided */
            ftpRequest.Credentials = new NetworkCredential(user, pass);
            /* When in doubt, use these options */
            ftpRequest.UseBinary = true;
            ftpRequest.UsePassive = true;
            ftpRequest.KeepAlive = true;
            /* Specify the Type of FTP Request */
            ftpRequest.Method = WebRequestMethods.Ftp.DeleteFile;
            /* Establish Return Communication with the FTP Server */
            ftpResponse = (FtpWebResponse)ftpRequest.GetResponse();
            /* Resource Cleanup */
            ftpResponse.Close();
            ftpRequest = null;
        }
        catch (Exception ex) { Console.WriteLine(ex.ToString()); }
        return;
    }
 
    /* Rename File */
    public void rename(string currentFileNameAndPath, string newFileName)
    {
        try
        {
            /* Create an FTP Request */
            ftpRequest = (FtpWebRequest)WebRequest.Create(host + "/" + currentFileNameAndPath);
            /* Log in to the FTP Server with the User Name and Password Provided */
            ftpRequest.Credentials = new NetworkCredential(user, pass);
            /* When in doubt, use these options */
            ftpRequest.UseBinary = true;
            ftpRequest.UsePassive = true;
            ftpRequest.KeepAlive = true;
            /* Specify the Type of FTP Request */
            ftpRequest.Method = WebRequestMethods.Ftp.Rename;
            /* Rename the File */
            ftpRequest.RenameTo = newFileName;
            /* Establish Return Communication with the FTP Server */
            ftpResponse = (FtpWebResponse)ftpRequest.GetResponse();
            /* Resource Cleanup */
            ftpResponse.Close();
            ftpRequest = null;
        }
        catch (Exception ex) { Console.WriteLine(ex.ToString()); }
        return;
    }
 
    /* Create a New Directory on the FTP Server */
    public void createDirectory(string newDirectory)
    {
        try
        {
            /* Create an FTP Request */
            ftpRequest = (FtpWebRequest)WebRequest.Create(host + "/" + newDirectory);
            /* Log in to the FTP Server with the User Name and Password Provided */
            ftpRequest.Credentials = new NetworkCredential(user, pass);
            /* When in doubt, use these options */
            ftpRequest.UseBinary = true;
            ftpRequest.UsePassive = true;
            ftpRequest.KeepAlive = true;
            /* Specify the Type of FTP Request */
            ftpRequest.Method = WebRequestMethods.Ftp.MakeDirectory;
            /* Establish Return Communication with the FTP Server */
            ftpResponse = (FtpWebResponse)ftpRequest.GetResponse();
            /* Resource Cleanup */
            ftpResponse.Close();
            ftpRequest = null;
        }
        catch (Exception ex) { Console.WriteLine(ex.ToString()); }
        return;
    }
 
    /* Get the Date/Time a File was Created */
    public string getFileCreatedDateTime(string fileName)
    {
        try
        {
            /* Create an FTP Request */
            ftpRequest = (FtpWebRequest)FtpWebRequest.Create(host + "/" + fileName);
            /* Log in to the FTP Server with the User Name and Password Provided */
            ftpRequest.Credentials = new NetworkCredential(user, pass);
            /* When in doubt, use these options */
            ftpRequest.UseBinary = true;
            ftpRequest.UsePassive = true;
            ftpRequest.KeepAlive = true;
            /* Specify the Type of FTP Request */
            ftpRequest.Method = WebRequestMethods.Ftp.GetDateTimestamp;
            /* Establish Return Communication with the FTP Server */
            ftpResponse = (FtpWebResponse)ftpRequest.GetResponse();
            /* Establish Return Communication with the FTP Server */
            ftpStream = ftpResponse.GetResponseStream();
            /* Get the FTP Server's Response Stream */
            StreamReader ftpReader = new StreamReader(ftpStream);
            /* Store the Raw Response */
            string fileInfo = null;
            /* Read the Full Response Stream */
            try { fileInfo = ftpReader.ReadToEnd(); }
            catch (Exception ex) { Console.WriteLine(ex.ToString()); }
            /* Resource Cleanup */
            ftpReader.Close();
            ftpStream.Close();
            ftpResponse.Close();
            ftpRequest = null;
            /* Return File Created Date Time */
            return fileInfo;
        }
        catch (Exception ex) { Console.WriteLine(ex.ToString()); }
        /* Return an Empty string Array if an Exception Occurs */
        return "";
    }
 
    /* Get the Size of a File */
    public string getFileSize(string fileName)
    {
        try
        {
            /* Create an FTP Request */
            ftpRequest = (FtpWebRequest)FtpWebRequest.Create(host + "/" + fileName);
            /* Log in to the FTP Server with the User Name and Password Provided */
            ftpRequest.Credentials = new NetworkCredential(user, pass);
            /* When in doubt, use these options */
            ftpRequest.UseBinary = true;
            ftpRequest.UsePassive = true;
            ftpRequest.KeepAlive = true;
            /* Specify the Type of FTP Request */
            ftpRequest.Method = WebRequestMethods.Ftp.GetFileSize;
            /* Establish Return Communication with the FTP Server */
            ftpResponse = (FtpWebResponse)ftpRequest.GetResponse();
            /* Establish Return Communication with the FTP Server */
            ftpStream = ftpResponse.GetResponseStream();
            /* Get the FTP Server's Response Stream */
            StreamReader ftpReader = new StreamReader(ftpStream);
            /* Store the Raw Response */
            string fileInfo = null;
            /* Read the Full Response Stream */
            try { while (ftpReader.Peek() != -1) { fileInfo = ftpReader.ReadToEnd(); } }
            catch (Exception ex) { Console.WriteLine(ex.ToString()); }
            /* Resource Cleanup */
            ftpReader.Close();
            ftpStream.Close();
            ftpResponse.Close();
            ftpRequest = null;
            /* Return File Size */
            return fileInfo;
        }
        catch (Exception ex) { Console.WriteLine(ex.ToString()); }
        /* Return an Empty string Array if an Exception Occurs */
        return "";
    }
 
    /* List Directory Contents File/Folder Name Only */
    public string[] directoryListSimple(string directory)
    {
        try
        {
            /* Create an FTP Request */
            ftpRequest = (FtpWebRequest)FtpWebRequest.Create(host + "/" + directory);
            /* Log in to the FTP Server with the User Name and Password Provided */
            ftpRequest.Credentials = new NetworkCredential(user, pass);
            /* When in doubt, use these options */
            ftpRequest.UseBinary = true;
            ftpRequest.UsePassive = true;
            ftpRequest.KeepAlive = true;
            /* Specify the Type of FTP Request */
            ftpRequest.Method = WebRequestMethods.Ftp.ListDirectory;
            /* Establish Return Communication with the FTP Server */
            ftpResponse = (FtpWebResponse)ftpRequest.GetResponse();
            /* Establish Return Communication with the FTP Server */
            ftpStream = ftpResponse.GetResponseStream();
            /* Get the FTP Server's Response Stream */
            StreamReader ftpReader = new StreamReader(ftpStream);
            /* Store the Raw Response */
            string directoryRaw = null;
            /* Read Each Line of the Response and Append a Pipe to Each Line for Easy Parsing */
            try { while (ftpReader.Peek() != -1) { directoryRaw += ftpReader.ReadLine() + "|"; } }
            catch (Exception ex) { Console.WriteLine(ex.ToString()); }
            /* Resource Cleanup */
            ftpReader.Close();
            ftpStream.Close();
            ftpResponse.Close();
            ftpRequest = null;
            /* Return the Directory Listing as a string Array by Parsing 'directoryRaw' with the Delimiter you Append (I use | in This Example) */
            try { string[] directoryList = directoryRaw.Split("|".ToCharArray()); return directoryList; }
            catch (Exception ex) { Console.WriteLine(ex.ToString()); }
        }
        catch (Exception ex) { Console.WriteLine(ex.ToString()); }
        /* Return an Empty string Array if an Exception Occurs */
        return new string[] { "" };
    }
 
    /* List Directory Contents in Detail (Name, Size, Created, etc.) */
    public string[] directoryListDetailed(string directory)
    {
        try
        {
            /* Create an FTP Request */
            ftpRequest = (FtpWebRequest)FtpWebRequest.Create(host + "/" + directory);
            /* Log in to the FTP Server with the User Name and Password Provided */
            ftpRequest.Credentials = new NetworkCredential(user, pass);
            /* When in doubt, use these options */
            ftpRequest.UseBinary = true;
            ftpRequest.UsePassive = true;
            ftpRequest.KeepAlive = true;
            /* Specify the Type of FTP Request */
            ftpRequest.Method = WebRequestMethods.Ftp.ListDirectoryDetails;
            /* Establish Return Communication with the FTP Server */
            ftpResponse = (FtpWebResponse)ftpRequest.GetResponse();
            /* Establish Return Communication with the FTP Server */
            ftpStream = ftpResponse.GetResponseStream();
            /* Get the FTP Server's Response Stream */
            StreamReader ftpReader = new StreamReader(ftpStream);
            /* Store the Raw Response */
            string directoryRaw = null;
            /* Read Each Line of the Response and Append a Pipe to Each Line for Easy Parsing */
            try { while (ftpReader.Peek() != -1) { directoryRaw += ftpReader.ReadLine() + "|"; } }
            catch (Exception ex) { Console.WriteLine(ex.ToString()); }
            /* Resource Cleanup */
            ftpReader.Close();
            ftpStream.Close();
            ftpResponse.Close();
            ftpRequest = null;
            /* Return the Directory Listing as a string Array by Parsing 'directoryRaw' with the Delimiter you Append (I use | in This Example) */
            try { string[] directoryList = directoryRaw.Split("|".ToCharArray()); return directoryList; }
            catch (Exception ex) { Console.WriteLine(ex.ToString()); }
        }
        catch (Exception ex) { Console.WriteLine(ex.ToString()); }
        /* Return an Empty string Array if an Exception Occurs */
        return new string[] { "" };
    }
}

HAVE FUN :)