edtFTPnet官方网站:
http://www.enterprisedt.com/products/edtftpnet/

目前最新版本为2.2.3,下载后在bin目录中找到edtFTPnet.dll,在项目中添加引用。
下面为一些用法:

1、FTP服务器根目录为web,在它下面创建如下图示的目录和上传文件
FTPConnection.CommandEncoding = Encoding.GetEncoding("GBK") 指定GBK编码以支持中文文件名
FTPConnection.CreateDirectory() 创建指定目录
FTPConnection.ChangeWorkingDirectory() 切换到指定目录
FTPConnection.UploadFile() 上传文件

web
|-----L11
      |-----L21            
            |-----L31
                  |-----31.htm
            |-----21.htm
      |-----L22
      |-----11.htm
      |-----目录.txt

+ View Code?
private const string ftpServerIP = "xx.xx.xx.xx";
private const string ftpRemotePath = "web";
private const string ftpUserID = "user";
private const string ftpPassword = "123";
 
private void btnCreateAndUpload_Click(object sender, EventArgs e)
{         
    using (var conn = new FTPConnection
    {
        ServerAddress = ftpServerIP,
        ServerDirectory = ftpRemotePath,
        UserName = ftpUserID,
        Password = ftpPassword,
        CommandEncoding = Encoding.GetEncoding("GBK")
    })
    {
        conn.Connect();               
 
        //创建目录L11
        conn.CreateDirectory("L11");
 
        //============切换当前工作目录到L11============
        conn.ChangeWorkingDirectory("L11");
        //上行代码也可以用conn.ServerDirectory = "L11";
 
        //上传"文档.txt"
        conn.UploadFile("文档.txt", "文档.txt");
 
        //创建子目录L21,L22
        conn.CreateDirectory("L21");
        conn.CreateDirectory("L22");
 
        //在当前工作目录L11上传文件"L11.htm"
        conn.UploadFile("11.htm", "11.htm");
 
        //============切换当前工作目录到L21============
        conn.ChangeWorkingDirectory("L21");
 
        //上传文件21.htm
        conn.UploadFile("21.htm", "21.htm");
        //创建目录L31
        conn.CreateDirectory("L31");
 
        //============切换当前工作目录到L31============
        conn.ChangeWorkingDirectory("L31");
 
        //上传文件31.htm
        conn.UploadFile("31.htm", "31.htm");
    }
}

2、获取文件信息
FTPConnection.GetFileInfos() 获取文件和目录详细信息,结果的一个属性Dir为true表示为目录,否则为文件

+ View Code?
private void btnList_Click(object sender, EventArgs e)
{
    using (var conn = new FTPConnection
    {
        ServerAddress = ftpServerIP,
        ServerDirectory = ftpRemotePath,
        UserName = ftpUserID,
        Password = ftpPassword,
        CommandEncoding = Encoding.GetEncoding("GBK")
    })
    {
        conn.Connect();
        //获取指定目录的所有子目录和文件信息
        conn.ChangeWorkingDirectory("L11/L21");              
        var files1 = conn.GetFileInfos();
        ShowFileInfos(files1);
        /*结果如下:
         File, /web/L11/L21/21.htm, 21.htm, 11.2KB, 2013-9-26 14:51:00
         Dir, /web/L11/L21/L31, L31, 0KB, 2013-9-26 14:51:00
         */
 
        ////返回上级目录,例子中为web/L11
        conn.ChangeWorkingDirectoryUp();
        var files2 = conn.GetFileInfosRecursive();
        ShowFileInfos(files2);
        /*结果如下:
        File, /web/L11/11.htm, 11.htm, 59.4KB, 2013-9-26 14:51:00
        Dir, /web/L11/L21, L21, 0KB, 2013-9-26 14:51:00
        Dir, /web/L11/L22, L22, 0KB, 2013-9-26 14:51:00
        File, /web/L11/文档.txt, 文档.txt, 40.8KB, 2013-9-26 14:51:00
        File, /web/L11/L21/21.htm, 21.htm, 11.2KB, 2013-9-26 14:51:00
        Dir, /web/L11/L21/L31, L31, 0KB, 2013-9-26 14:51:00
        File, /web/L11/L21/L31/31.htm, 31.htm, 5.6KB, 2013-9-26 14:51:00
         */
    }
}     
void ShowFileInfos(FTPFile[] files)
{
    foreach (var file in files)
    {
        string info = string.Format("{0}, {1}, {2}, {3}KB, {4}",
            file.Dir ? "Dir" : "File", file.Path, file.Name, Math.Round(file.Size / 1024.0, 1), file.LastModified);
        richTextBox1.AppendText(info + "\r\n");
    }
    richTextBox1.AppendText("\r\n");
}

其中递归获取指定目录的所有子目录和文件信息的扩展方法GetFileInfosRecursive如下:

+ View Code?
public static class FtpClientExtensions
{
    /// <summary>
    /// 递归获取目录的所有子目录和文件信息
    /// </summary>
    public static FTPFile[] GetFileInfosRecursive(this FTPConnection conn)
    {
        var resultList = new List<FTPFile>();
        var fileInfos = conn.GetFileInfos();
        resultList.AddRange(fileInfos);
        foreach (var fileInfo in fileInfos)
        {
            if (fileInfo.Dir)
            {
                conn.ServerDirectory = fileInfo.Path;
                resultList.AddRange(conn.GetFileInfosRecursive());
            }
        }
        return resultList.ToArray();
    }
    /// <summary>
    /// 递归删除目录(包括所有子目录和文件信息)
    /// </summary>
    public static void DeleteDirectoryRecursive(this FTPConnection conn, string directoryName)
    {
        conn.ChangeWorkingDirectory(directoryName);
        var fileInfos = conn.GetFileInfos();
        foreach (var fileInfo in fileInfos)
        {
            if (fileInfo.Dir)
                conn.DeleteDirectoryRecursive(fileInfo.Name);
            else
                conn.DeleteFile(fileInfo.Name);
        }
        conn.ChangeWorkingDirectoryUp();
        conn.DeleteDirectory(directoryName);
    }
}

3、删除目录及所有子目录和文件
FTPConnection.DeleteDirectory()当删除的目录不为空时,会出错,需递归删除,
递归删除目录扩展方法DeleteDirectoryRecursive见上面类FtpClientExtensions

+ View Code?
private void btnDelete_Click(object sender, EventArgs e)
{
    using (var conn = new FTPConnection
    {
        ServerAddress = ftpServerIP,
        ServerDirectory = ftpRemotePath,
        UserName = ftpUserID,
        Password = ftpPassword,
        CommandEncoding = Encoding.GetEncoding("GBK")
    })
    {
        conn.Connect();             
        //递归删除目录及所有子目录和文件
        conn.DeleteDirectoryRecursive("L11");
        //如果删除单个文件,路径为当前目录的相对路径
        //conn.DeleteFile("L11/11.htm");
    }
}