在附件管理模块中增加对FTP 上传和预览的支持

//create an FTP client
FtpClient client = new FtpClient("123.123.123.123");//if you don't specify login credentials, we use the "anonymous" user account
client.Credentials = new NetworkCredential("david", "pass123");//begin connecting to the server
client.Connect();//get a list of files and directories in the "/htdocs" folder
foreach (FtpListItem item in client.GetListing("/htdocs")) {//if this is a file
    if (item.Type ==FtpFileSystemObjectType.File){//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);

    

}//upload a file
client.UploadFile(@"C:\MyVideo.mp4", "/htdocs/big.txt");//rename the uploaded file
client.Rename("/htdocs/big.txt", "/htdocs/big2.txt");//download the file again
client.DownloadFile(@"C:\MyVideo_2.mp4", "/htdocs/big2.txt");//delete the file
client.DeleteFile("/htdocs/big2.txt");//delete a folder recursively
client.DeleteDirectory("/htdocs/extras/");//check if a file exists
if (client.FileExists("/htdocs/big2.txt")){ }//check if a folder exists
if (client.DirectoryExists("/htdocs/extras/")){ }//upload a file and retry 3 times before giving up
client.RetryAttempts = 3;

client.UploadFile(@"C:\MyVideo.mp4", "/htdocs/big.txt", FtpExists.Overwrite, false, FtpVerify.Retry);//disconnect! good bye!
client.Disconnect();

    /// <summary>
    ///FTP配置信息/// </summary>
[DataContract]

    [Serializable]public classFTPInfo

    {/// <summary>
        ///默认构造函数/// </summary>
        publicFTPInfo()

        {



        }/// <summary>
        ///参数化构造函数/// </summary>
        /// <param name="server"></param>
        /// <param name="user"></param>
        /// <param name="password"></param>
        public FTPInfo(string server, string user, string password, stringbaseUrl)

        {this.Server =server;this.User =user;this.Password =password;this.BaseUrl =baseUrl;

        }/// <summary>
        ///FTP服务地址/// </summary>
[DataMember]public string Server { get; set; }/// <summary>
        ///FTP用户名/// </summary>
[DataMember]public string User { get; set; }/// <summary>
        ///FTP密码/// </summary>
[DataMember]public string Password { get; set; }/// <summary>
        ///FTP的基础路径，如可以指定为IIS的路径：http://www.iqidi.com:8000 ,方便下载打开/// </summary>
[DataMember]public string BaseUrl { get; set; }

    }

        /// <summary>
        ///获取配置的FTP配置参数/// </summary>
        /// <returns></returns>
        privateFTPInfo GetFTPConfig()

        {var ftp_server = config.AppConfigGet("ftp_server");var ftp_user = config.AppConfigGet("ftp_user");var ftp_pass = config.AppConfigGet("ftp_password");var ftp_baseurl = config.AppConfigGet("ftp_baseurl");return newFTPInfo(ftp_server, ftp_user, ftp_pass, ftp_baseurl);

        }

//使用FluentFTP操作FTP文件
FtpClient client = new FtpClient(ftpInfo.Server, ftpInfo.User, ftpInfo.Password);

//确定日期时间目录（格式：yyyy-MM），不存在则创建
string savePath = string.Format("/{0}-{1:D2}/{2}", DateTime.Now.Year, DateTime.Now.Month, category);bool isExistDir =client.DirectoryExists(savePath);if(!isExistDir)

{

    client.CreateDirectory(savePath);

}

//使用FTP上传文件//避免文件重复，使用GUID命名
var ext =FileUtil.GetExtension(info.FileName);var newFileName = string.Format("{0}{1}", Guid.NewGuid().ToString(), ext);//FileUtil.GetFileName(file);
savePath=savePath.UriCombine(newFileName);bool uploaded = client.Upload(info.FileData, savePath, FtpExists.Overwrite, true);