各位大哥您好，请指教小弟一点，不胜感谢！

Question

1、不是用什么技术，而是协议
2、可以使用Indy或ICS系列internet控件，均可实现FTP客户端与服务器

Answer 1

SOCKET与FTP都可以
这个不是一句话可以说完的，多看一看书吧

Answer 2

用socket方便一些，
必须先执行一个socket server程序，delphi内附这个程序：Borland\Delphi5\Bin\scktsrvr.exe

Answer 3

FTP:delphi中的nmftp控件中Download函数只能下载一个文件，没有提供一个下载整个目录（包含子目录）的函数。
我编写了个实现目录下载功能的方法，需要用到该功能的用户可参考一下。
file://目录下载
function tftp.ex_download(remote_dir,local_dir:string):boolean;
var
    i,j,count1:integer;
    att,ss:string;
    current_dir:string;
    temp_dir:string;
begin
    try begin
        NMFTP1.ChangeDir(remote_dir);
        current_dir:=remote_dir;
        temp_dir:=copy(current_dir,2,length(current_dir));
        if not DirectoryExists(local_dir) then CreateDir(local_dir);
        if not directoryexists(local_dir+temp_dir) then createdir(local_dir+temp_dir);
        nmftp1.ParseList:=true;
        NMftp1.list;
        count1:=nmftp1.FTPDirectoryList.name.Count;
        for i:=0 to count1-1  do begin
            file://必须
            NMFTP1.ChangeDir(current_dir);
            nmftp1.list;
            ss:=nmftp1.FTPDirectoryList.name.Strings[i];
            att:=nmftp1.FTPDirectoryList.Attribute.Strings[i];
            if (copy(pchar(att),1,1)<>'d')and(copy(pchar(att),1,1)<>'D') then begin
                if not DirectoryExists(local_dir) then CreateDir(local_dir);
                NMFTP1.Download(current_dir+ss,local_dir+temp_dir+ss);
            end
            else begin
                if not directoryexists(local_dir+temp_dir+ss) then createdir(local_dir+temp_dir+ss);
                file://递归调用
                ex_download(remote_dir+ss+'\',local_dir);
            end;
        end;
           result:=true;
    end
    except
    On E:Exception do begin
        result:=false;
    end;
    end;
end;

Answer 4

SOCKET:SOCKET传文件的例子：
unit Unit1;interfaceuses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  ScktComp, StdCtrls;type
  TCon = record
    FileName : String;
    TotalSize : Integer;
    Status : Integer;
  end;  PCON = ^TCON;  TForm1 = class(TForm)
    SS: TServerSocket;
    Button1: TButton;
    Button2: TButton;
    procedure Button1Click(Sender: TObject);
    procedure SSClientConnect(Sender: TObject; Socket: TCustomWinSocket);
    procedure SSClientRead(Sender: TObject; Socket: TCustomWinSocket);
    procedure Button2Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;var
  Form1: TForm1;implementationuses Unit2;{$R *.DFM}procedure TForm1.Button1Click(Sender: TObject);
begin
    SS.Port := 9000;
    SS.Active := True;
end;procedure TForm1.SSClientConnect(Sender: TObject;
  Socket: TCustomWinSocket);
var c : pcon;
begin    c :=new(pcon);
    c.FileName := '';
    c.TotalSize :=  0 ;
    c.Status := 0;
    Socket.Data := c;
    Socket.SendText('已经连接,请输入UPLOAD FILENAME SIZE'#13#10);end;procedure TForm1.SSClientRead(Sender: TObject; Socket: TCustomWinSocket);
var C : PCON;
    cmd:String;
    Buffer : pointer;
    nRetr : integer;
    fs : TFileStream;
const bufferSize =  1024 ;begin
    C:= Socket.Data ;
    case c.Status of
        0 :
        begin
               cmd := trim(Socket.ReceiveText) ;               if  Pos('UPLOAD ',uppercase(cmd)) >  0 then
               begin
                    c.FileName := trim(Copy(cmd,Pos(' ',cmd)+1,Length(cmd)));
                    c.TotalSize := StrToInt(Copy(c.FileName,Pos(' ',c.FileName)+1,Length(c.FileName)));
                    c.FileName := trim(Copy(c.FileName,1,Pos(' ',c.FileName)));
                    c.Status := 1;
                    Socket.Data := C;
                    Socket.SendText('you can send File  !'#13#10);
               end;
            end;
        1 : begin
                GetMem(Buffer,BufferSize);
                nRetr := Socket.ReceiveBuf(Buffer^,BufferSize);                if not FIleExists('c:\'+c.FileName) then
                begin
                     fs :=TFileStream.Create('c:\'+c.FileName,fmCreate or fmShareDenyNone);
                     fs.Seek(0,soFromBeginning);
                end
                else
                begin
                     fs :=TFileStream.Create('c:\'+c.FileName,fmOpenWrite or fmShareDenyNone);
                     fs.Seek(0,soFromEnd);
                end;                fs.WriteBuffer(Buffer^,nRetr);                fs.Destroy;
                FreeMem(Buffer);
            end;
    end;
end;procedure TForm1.Button2Click(Sender: TObject);
begin
    Form2.Show;
end;end. 
 --------------------------------------------------------------------------------
来自：唐晓锋 时间：99-11-30 01:17:19 ID:162654 
unit Unit2;interfaceuses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  StdCtrls, ScktComp;type
  TForm2 = class(TForm)
    CS: TClientSocket;
    OpenDialog1: TOpenDialog;
    Memo1: TMemo;
    Button1: TButton;
    Edit1: TEdit;
    Button2: TButton;
    SendCommand: TButton;
    Label1: TLabel;
    Button3: TButton;
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
    procedure SendCommandClick(Sender: TObject);
    procedure Button3Click(Sender: TObject);
    procedure CSRead(Sender: TObject; Socket: TCustomWinSocket);
  private
    { Private declarations }
  public
    { Public declarations }
  end;var
  Form2: TForm2;implementation{$R *.DFM}
function GetFileSize(const FileName: string):integer;
var f : TFileStream;
begin
    f := TFileStream.Create(FileName,fmOpenRead or fmShareDenyNone);
    Result :=f.Size;
    F.Free;
end;
procedure TForm2.Button1Click(Sender: TObject);
begin
    with OpenDialog1 do
    begin
        Execute;
        if FileName <> '' then
        begin
            Edit1.Text := 'UPLOAD '+ ExtractFileName(FileName) +' '+Inttostr(GetFileSize(FileName));
            Label1.Caption := FileName;
            cs.Socket.SendText(edit1.Text);
        end;
    end;
end;procedure TForm2.Button2Click(Sender: TObject);
begin
    CS.Active := True;end;procedure TForm2.SendCommandClick(Sender: TObject);
var fs : TFileStream;
    Buf : pointer;begin
    //CS.Socket.SendText(Edit1.Text+#13#10);
    //Memo1.Lines.Add();
    fs := TFileStream.Create(Label1.Caption ,fmOpenRead or fmShareDenyNone);    GetMem(Buf,fs.Size);
    fs.Seek(0,soFromBeginning);    fs.ReadBuffer(Buf^,fs.Size);    memo1.Lines.Add('has send : '+inttostr(Cs.Socket.SendBuf(Buf^,fs.Size)));end;procedure TForm2.Button3Click(Sender: TObject);
begin
    cs.Close;
end;procedure TForm2.CSRead(Sender: TObject; Socket: TCustomWinSocket);
begin   Memo1.Lines.add(socket.receiveText);end;end.