FTP ด้วย WebRequest มีปัญหากับไฟล์ PDF แต่ถ้าใช้ไลบรารี WinSCP ไม่มีปัญหา

1. FTP – Download Files
2. FTP – Upload Files
3. FTP – List Directory Contents
4. FTP – Create Directory

• FTP
• FtpWebRequest Class
• FtpWebResponse Class

1.FTP – Download Files

using System;
using System.IO;
using System.Net;

namespace Examples.System.Net
{
    public class WebRequestGetExample
    {
        public static void Main ()
        {
            // Get the object used to communicate with the server.
            FtpWebRequest request = (FtpWebRequest)WebRequest.Create("ftp://www.contoso.com/test.htm");
            request.Method = WebRequestMethods.Ftp.DownloadFile;

            // This example assumes the FTP site uses anonymous logon.
            request.Credentials = new NetworkCredential("anonymous","janeDoe@contoso.com");

            FtpWebResponse response = (FtpWebResponse)request.GetResponse();

            Stream responseStream = response.GetResponseStream();
            StreamReader reader = new StreamReader(responseStream);
            Console.WriteLine(reader.ReadToEnd());

            Console.WriteLine($"Download Complete, status {response.StatusDescription}");

            reader.Close();
            response.Close();
        }
    }
}

หรืออ่านค่าจาก config แบบนี้

using System;
using System.Configuration;
using System.IO;
using System.Net;

namespace ConsoleApp1
{
    class Program
    {
        static void Main(string[] args)
        {
            string FTPServer = ConfigurationManager.AppSettings.Get("FTPServer");
            string FTPUserName = ConfigurationManager.AppSettings.Get("FTPUserName");
            string FTPPassword = ConfigurationManager.AppSettings.Get("FTPPassword");

            string filename = "/test.txt";
            string downloadUrl = string.Format("ftp://{0}//{1}", FTPServer, filename);
            FtpWebRequest request = (FtpWebRequest)WebRequest.Create(downloadUrl);
            request.Method = WebRequestMethods.Ftp.DownloadFile;
            request.Credentials = new NetworkCredential(FTPUserName, FTPPassword);

            using (FtpWebResponse response = (FtpWebResponse)request.GetResponse())
            {
                using (Stream responseStream = response.GetResponseStream())
                {
                    using (StreamReader reader = new StreamReader(responseStream))
                    {
                        Console.WriteLine(reader.ReadToEnd());
                    }
                }
            }
        }
    }
}

เมื่อรันจะอ่านข้อความในไฟล์ที่กำหนด ออกมาทางหน้าจอ

หรือถ้าจะ save เป็นไฟล์ ให้เปลี่ยนบรรทัดที่ 30-33 เป็น

string downloadfileName = "x.txt";
using (FileStream writeStream = new FileStream(downloadfileName, FileMode.Create))
{
    int Length = 2048;
    Byte[] buffer = new Byte[Length];
    int bytesRead = responseStream.Read(buffer, 0, Length);
    while (bytesRead > 0)
    {
        writeStream.Write(buffer, 0, bytesRead);
        bytesRead = responseStream.Read(buffer, 0, Length);
    }
}

2.FTP – Upload Files

• How to: Upload files with FTP

using System;
using System.IO;
using System.Net;
using System.Text;

namespace Examples.System.Net
{
    public class WebRequestGetExample
    {
        public static void Main ()
        {
            // Get the object used to communicate with the server.
            FtpWebRequest request = (FtpWebRequest)WebRequest.Create("ftp://www.contoso.com/test.htm");
            request.Method = WebRequestMethods.Ftp.UploadFile;

            // This example assumes the FTP site uses anonymous logon.
            request.Credentials = new NetworkCredential("anonymous", "janeDoe@contoso.com");

            // Copy the contents of the file to the request stream.
            byte[] fileContents;
            using (StreamReader sourceStream = new StreamReader("testfile.txt"))
            {
                fileContents = Encoding.UTF8.GetBytes(sourceStream.ReadToEnd());
            }

            request.ContentLength = fileContents.Length;

            using (Stream requestStream = request.GetRequestStream())
            {
                requestStream.Write(fileContents, 0, fileContents.Length);
            }

            using (FtpWebResponse response = (FtpWebResponse)request.GetResponse())
            {
                Console.WriteLine($"Upload File Complete, status {response.StatusDescription}");
            }
        }
    }
}

3.FTP – List Directory Contents

• How to: List directory contents with FTP

using System;
using System.IO;
using System.Net;

namespace Examples.System.Net
{
    public class WebRequestGetExample
    {
        public static void Main ()
        {
            // Get the object used to communicate with the server.
            FtpWebRequest request = (FtpWebRequest)WebRequest.Create("ftp://www.contoso.com/");
            request.Method = WebRequestMethods.Ftp.ListDirectoryDetails;

            // This example assumes the FTP site uses anonymous logon.
            request.Credentials = new NetworkCredential ("anonymous","janeDoe@contoso.com");

            FtpWebResponse response = (FtpWebResponse)request.GetResponse();

            Stream responseStream = response.GetResponseStream();
            StreamReader reader = new StreamReader(responseStream);
            Console.WriteLine(reader.ReadToEnd());

            Console.WriteLine($"Directory List Complete, status {response.StatusDescription}");

            reader.Close();
            response.Close();
        }
    }
}

4.FTP – Create Directory

public static bool CreateDirectory(string remoteFolder)
{
    try
    {
        log.Info(string.Format("Parameter ('{0}')", remoteFolder));

        // FTP server config
        string FTPServer = ConfigurationManager.AppSettings.Get("FTPServer");
        string FTPUserName = ConfigurationManager.AppSettings.Get("FTPUserName");
        string FTPPassword = ConfigurationManager.AppSettings.Get("FTPPassword");

        WebRequest request = WebRequest.Create(string.Format("ftp://{0}/{1}", FTPServer, remoteFolder));
        request.Method = WebRequestMethods.Ftp.MakeDirectory;
        request.Credentials = new NetworkCredential(FTPUserName, FTPPassword);
        using (var resp = (FtpWebResponse)request.GetResponse())
        {
            log.Info(resp.StatusCode);
        }

        return true;
    }
    catch (Exception e)
    {
        log.Error(string.Format("Error: {0}", e.Message));
        return false;
    }
}