How to transfer multiple files from FTP server to local directory using C#?

问题

I can transfer one file from ftp server to local directory. using the following code

  using (WebClient ftpClient = new WebClient())
        {
            ftpClient.Credentials = new System.Net.NetworkCredential("username", "password");
            ftpClient.DownloadFile("ftp://website.com/abcd.docx", @"D:\\WestHam\test.docx");

but i don't know how to transfer multiple files. can anybody help me on this. }

回答1:

Use this code, just replace the user credentials:

static void Main(string[] args)
{
    FtpWebRequest ftpRequest = (FtpWebRequest)WebRequest.Create("ftp://mywebsite.com/");
    ftpRequest.Credentials = new NetworkCredential("user345", "pass234");
    ftpRequest.Method = WebRequestMethods.Ftp.ListDirectory;
    FtpWebResponse response = (FtpWebResponse)ftpRequest.GetResponse();
    StreamReader streamReader = new StreamReader(response.GetResponseStream());           
    List<string> directories = new List<string>();            

    string line = streamReader.ReadLine();
    while (!string.IsNullOrEmpty(line))
    {
        directories.Add(line);
        line = streamReader.ReadLine();
    }
    streamReader.Close();


    using (WebClient ftpClient = new WebClient())
    {
        ftpClient.Credentials = new System.Net.NetworkCredential("user345", "pass234");

        for (int i = 0; i <= directories.Count-1; i++)
        {
            if (directories[i].Contains("."))
            {

                string path = "ftp://mywebsite.com/" + directories[i].ToString();
                string trnsfrpth = @"D:\\Test\" + directories[i].ToString();
                ftpClient.DownloadFile(path, trnsfrpth);
            }
        }
    }

回答2:

Very Great and simple library FluentFTP

Check it out;

My config file:

<?xml version="1.0" encoding="utf-8" ?> <configuration> <startup> <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.6.1" /> </startup> <appSettings> <add key="FtpHost" value="127.0.0.1"/> <add key="FtpUser" value="username"/> <add key="FtpPassword" value="password123"/> <add key="FtpDirectory" value="/INTERESTING FILES/DATA"/> <add key="FileExtension" value=".txt"/> <add key="DownloadTo" value="C:\Downloads"/> <add key="DeleteFilesAfterDownload" value="false"/> </appSettings> </configuration>

And a little FTP Library:

namespace FTPDownloadAdapter {
    class Program
    {
        private static readonly string FtpHost = ConfigurationManager.AppSettings["FtpHost"];
        private static readonly string FtpUser = ConfigurationManager.AppSettings["FtpUser"];
        private static readonly string FtpPassword = ConfigurationManager.AppSettings["FtpPassword"];
        private static readonly string FtpDirectory = ConfigurationManager.AppSettings["FtpDirectory"];
        private static readonly string FileExtension = ConfigurationManager.AppSettings["FileExtension"];
        private static readonly string DownloadTo = ConfigurationManager.AppSettings["DownloadTo"];
        private static readonly string DeleteFilesAfterDownload = ConfigurationManager.AppSettings["DeleteFilesAfterDownload"];

        static void Main(string[] args)
        {


            try{


                DownloadFiles();


            }
            catch (Exception er){
                Console.WriteLine(er.ToString());
            }

        }

        private static void DownloadFiles(){

            // create an FTP client
            var client = new FtpClient(FtpHost) { Credentials = new NetworkCredential(FtpUser, FtpPassword) };

            // if you don't specify login credentials, we use the "anonymous" user account


            // begin connecting to the server
            client.Connect();


            Console.WriteLine($"Retrieving files with extension [{FileExtension}] from directory [{FtpDirectory}]");



            foreach (FtpListItem item in client.GetListing(FtpDirectory)){

                // if this is a file
                if (item.Type == FtpFileSystemObjectType.File && (Path.GetExtension(item.FullName) == FileExtension)){

                    // get the file size
                    long size = client.GetFileSize(item.FullName);

                    // get modified date/time of the file or folder
                    DateTime time = client.GetModifiedTime(item.FullName);

                    // calculate a hash for the file on the server side (default algorithm)
                    FtpHash hash = client.GetHash(item.FullName);

                    // download the file 
                    var fileName = Path.GetFileName(item.FullName);
                    var saveFilePath = Path.Combine(DownloadTo, fileName ?? throw new InvalidOperationException("File Appears to not have a name"));

                    Console.WriteLine($"Downloading file: {fileName}");

                    client.DownloadFile(localPath: saveFilePath, remotePath: item.FullName);

                    if (DeleteFilesAfterDownload == "true")
                    {
                        Console.WriteLine($"DeleteFilesAfterDownload is true, Deleting file from FTP : {item.FullName}");

                        client.DeleteFile(item.FullName);

                        Console.WriteLine("File deletion success");
                    }
                    else
                    {

                        Console.WriteLine($"DeleteFilesAfterDownload not true, skip deleting : {item.FullName}");

                    }

                }
            }
        }
    }
}

来源：https://stackoverflow.com/questions/20526536/how-to-transfer-multiple-files-from-ftp-server-to-local-directory-using-c