ClientSocket組件為客戶端組件膳沽。它是通信的請(qǐng)求方近上，也就是說交排，它是主動(dòng)地與服務(wù)器端建立連接斯辰。

ServerSocket組件為服務(wù)器端組件绍刮。它是通信的響應(yīng)方腋粥，也就是說魂贬，它的動(dòng)作是監(jiān)聽以及被動(dòng)接受客戶端的連接請(qǐng)求甫窟，并對(duì)請(qǐng)求進(jìn)行回復(fù)。

【以下內(nèi)容轉(zhuǎn)自http://blog.csdn.net/dainiao01/article/details/2694257】
本例包括一個(gè)服務(wù)器端程序和一個(gè)客戶端程序种冬×统螅客戶端程序可以放到多個(gè)計(jì)算機(jī)上運(yùn)行，同時(shí)與服務(wù)器端進(jìn)行連接
通信娱两。

本例的重點(diǎn)莺匠，一是演示客戶端與服務(wù)器端如何通信；二是當(dāng)有多個(gè)客戶端同時(shí)連接到服務(wù)器端時(shí)十兢，服務(wù)器端如何識(shí)
別每個(gè)客戶端趣竣，并對(duì)請(qǐng)求給出相應(yīng)的回復(fù)。為了保證一個(gè)客戶端斷開連接時(shí)不影響其它客戶端與服務(wù)器端的通信旱物，
同時(shí)保證服務(wù)器端能夠正確回復(fù)客戶端的請(qǐng)求遥缕，在本例中聲明了一個(gè)記錄類型：

服務(wù)器端源碼（uServerMain.pas）：

unit uServerMain;

interface

uses
Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
ScktComp, ToolWin, ComCtrls, ExtCtrls, StdCtrls, Buttons;

const
CMax=10; //客戶端最大連接數(shù)

type
client_record=record
CHandle: integer; //客戶端套接字句柄
CSocket:TCustomWinSocket; //客戶端套接字
CName:string; //客戶端計(jì)算機(jī)名稱
CAddress:string; //客戶端計(jì)算機(jī)IP地址
CUsed: boolean; //客戶端聯(lián)機(jī)標(biāo)志

end;

type
  TfrmServerMain = class(TForm)
  ServerSocket: TServerSocket;
  ControlBar1: TControlBar;
  ToolBar1: TToolBar;
  tbConnect: TToolButton;
  tbClose: TToolButton;
  tbDisconnected: TToolButton;
  Edit1: TEdit;
  Memo1: TMemo;
  StatusBar: TStatusBar;
  procedure tbConnectClick(Sender: TObject);
  procedure tbDisconnectedClick(Sender: TObject);
  procedure ServerSocketClientRead(Sender: TObject;
  Socket: TCustomWinSocket);
  procedure ServerSocketListen(Sender: TObject;
  Socket: TCustomWinSocket);
  procedure ServerSocketClientConnect(Sender: TObject;  Socket: TCustomWinSocket);
  procedure ServerSocketClientDisconnect(Sender: TObject;  Socket: TCustomWinSocket);
  procedure tbCloseClick(Sender: TObject);
  procedure FormCreate(Sender: TObject);
  procedure FormClose(Sender: TObject; var Action: TCloseAction);
  procedure ServerSocketGetSocket(Sender: TObject; Socket: Integer;  var ClientSocket: TServerClientWinSocket);
  procedure ServerSocketClientError(Sender: TObject;  Socket: TCustomWinSocket; ErrorEvent: TErrorEvent;  var ErrorCode: Integer);
  
  private
    { Private declarations }
  public
    { Public declarations }
    session: array[0..CMax] of client_record; //客戶端連接數(shù)組
    Sessions: integer; //客戶端連接數(shù)
end;

var
  frmServerMain: TfrmServerMain;

implementation
{$R *.DFM}

//打開套接字連接，并使套接字進(jìn)入監(jiān)聽狀態(tài)
procedure TfrmServerMain.tbConnectClick(Sender: TObject);
begin
  ServerSocket.Open ;
end;

//關(guān)閉套接字連接宵呛，不再監(jiān)聽客戶端的請(qǐng)求
procedure TfrmServerMain.tbDisconnectedClick(Sender: TObject);
begin
  ServerSocket.Close;
  StatusBar.Panels[0].Text :=服務(wù)器套接字連接已經(jīng)關(guān)閉单匣，無法接受客戶端的連接請(qǐng)求.;
end;

//從客戶端讀取信息
procedure TfrmServerMain.ServerSocketClientRead(Sender: TObject; 
 Socket: TCustomWinSocket);
var
  i:integer;
begin
  //將從客戶端讀取的信息添加到Memo1中
  Memo1.Lines.Add(Socket.ReceiveText);
  for i:=0 to sessions do
  begin
    //取得匹配的客戶端
    if session[i].CHandle = Socket.SocketHandle then
    begin
      session[i].CSocket.SendText(回復(fù)客戶端+session[i].CAddress+ ==> +Edit1.Text);
    end;
  end;
end;

//服務(wù)器端套接字進(jìn)入監(jiān)聽狀態(tài)，以便監(jiān)聽客戶端的連接
procedure TfrmServerMain.ServerSocketListen(Sender: TObject;
Socket: TCustomWinSocket);
begin
    StatusBar.Panels[0].Text :=等待客戶端連接...;
end;
//當(dāng)客戶端連接到服務(wù)器端以后
procedure TfrmServerMain.ServerSocketClientConnect(Sender: TObject;
Socket: TCustomWinSocket);
var
i,j:integer;
begin
j:=-1;
for i:=0 to sessions do
begin
//在原有的客戶端連接數(shù)組中有中斷的客戶端連接
if not session[i].CUsed then
begin
session[i].CHandle := Socket.SocketHandle ;//客戶端套接字句柄
session[i].CSocket := Socket; //客戶端套接字
session[i].CName := Socket.RemoteHost ; //客戶端計(jì)算機(jī)名稱
session[i].CAddress := Socket.RemoteAddress ;//客戶端計(jì)算機(jī)IP
session[i].CUsed := True; //連接數(shù)組當(dāng)前位置已經(jīng)占用
Break;
end;
j:=i;
end;
if j=sessions then
begin
inc(sessions);
session[j].CHandle := Socket.SocketHandle ;
session[j].CSocket := Socket;
session[j].CName := Socket.RemoteHost ;
session[j].CAddress := Socket.RemoteAddress ;
session[j].CUsed := True;
end;
StatusBar.Panels[0].Text := 客戶端 +Socket.RemoteHost + 已經(jīng)連接;
end;
//當(dāng)客戶端斷開連接時(shí)
procedure TfrmServerMain.ServerSocketClientDisconnect(Sender: TObject;
Socket: TCustomWinSocket);
var
  i:integer;
  begin
    for i:=0 to sessions do
    begin
      if session[i].CHandle =Socket.SocketHandle then
      begin
        session[i].CHandle :=0;
        session[i].CUsed := False;
        Break;
      end;
    end;
    StatusBar.Panels[0].Text :=客戶端 +Socket.RemoteHost + 已經(jīng)斷開;
  end;

//關(guān)閉窗口
procedure TfrmServerMain.tbCloseClick(Sender: TObject);
begin
  Close;
end;

procedure TfrmServerMain.FormCreate(Sender: TObject);
begin
  sessions := 0;
end;

procedure TfrmServerMain.FormClose(Sender: TObject;
var Action: TCloseAction);
begin
  ServerSocket.Close ;
end;

//當(dāng)客戶端正在與服務(wù)器端連接時(shí)
procedure TfrmServerMain.ServerSocketGetSocket(Sender: TObject;
Socket: Integer; var ClientSocket: TServerClientWinSocket);
begin
    StatusBar.Panels[0].Text :=客戶端正在連接...;
end;

//客戶端發(fā)生錯(cuò)誤
procedure TfrmServerMain.ServerSocketClientError(Sender: TObject;
Socket: TCustomWinSocket; ErrorEvent: TErrorEvent;
var ErrorCode: Integer);
begin
    StatusBar.Panels[0].Text :=客戶端+Socket.RemoteHost +發(fā)生錯(cuò)誤宝穗！;
ErrorCode := 0;
end;

end.

客戶端源碼(uClientMain.pas)：

unit uClientMain;

interface

uses
Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
ScktComp, ComCtrls, ToolWin, ExtCtrls, StdCtrls, Buttons;

const
  SocketHost = 172.16.1.6; //服務(wù)器端地址

type
  TfrmClientMain = class(TForm)
  ControlBar1: TControlBar;
  ToolBar1: TToolBar;
  tbConnected: TToolButton;
  tbSend: TToolButton;
  tbClose: TToolButton;
  tbDisconnected: TToolButton;
  ClientSocket: TClientSocket;
  Edit1: TEdit;
  Memo1: TMemo;
  StatusBar: TStatusBar;
  btnSend: TBitBtn;
  procedure tbConnectedClick(Sender: TObject);
  procedure tbDisconnectedClick(Sender: TObject);
  procedure ClientSocketRead(Sender: TObject; Socket: TCustomWinSocket);
  procedure tbSendClick(Sender: TObject);
  procedure tbCloseClick(Sender: TObject);
  procedure FormShow(Sender: TObject);
  procedure ClientSocketConnect(Sender: TObject;
  Socket: TCustomWinSocket);
  procedure ClientSocketConnecting(Sender: TObject;
  Socket: TCustomWinSocket);
  procedure ClientSocketDisconnect(Sender: TObject;
  Socket: TCustomWinSocket);
  procedure FormClose(Sender: TObject; var Action: TCloseAction);
  procedure ClientSocketError(Sender: TObject; Socket: TCustomWinSocket;
  ErrorEvent: TErrorEvent; var ErrorCode: Integer);
  private
    { Private declarations }
  public
    { Public declarations }
end;

var
  frmClientMain: TfrmClientMain;

implementation
  {$R *.DFM}

//打開套接字連接
procedure TfrmClientMain.tbConnectedClick(Sender: TObject);
begin
  ClientSocket.Open ;
end;

//關(guān)閉套接字連接
procedure TfrmClientMain.tbDisconnectedClick(Sender: TObject);
begin
  ClientSocket.Close;
end;

//接受服務(wù)器端的回復(fù)
procedure TfrmClientMain.ClientSocketRead(Sender: TObject;
Socket: TCustomWinSocket);
begin
  Memo1.Lines.Add(Socket.ReceiveText);
end;

//發(fā)送信息到服務(wù)器端
procedure TfrmClientMain.tbSendClick(Sender: TObject);
begin
  ClientSocket.Socket.SendText(Edit1.Text); 
end;

procedure TfrmClientMain.tbCloseClick(Sender: TObject);
begin
  Close;
end;

//設(shè)置要連接的服務(wù)器端地址
procedure TfrmClientMain.FormShow(Sender: TObject);
begin
  ClientSocket.Host := SocketHost;
end;
//已經(jīng)連接到服務(wù)器端
procedure TfrmClientMain.ClientSocketConnect(Sender: TObject;
Socket: TCustomWinSocket);
begin
  tbSend.Enabled := True;
  tbDisconnected.Enabled :=True;
  btnSend.Enabled := True;
  StatusBar.Panels[0].Text := 已經(jīng)連接到 + Socket.RemoteHost ;
end;

//正在連接到服務(wù)器端
//(***本文出處：南山古桃(nsgtao)的百度空間：http://hi.baidu.com/nsgtao/ ****)
procedure TfrmClientMain.ClientSocketConnecting(Sender: TObject;
Socket: TCustomWinSocket);
begin
  StatusBar.Panels[0].Text := 正在連接到服務(wù)器... ;
end;
//當(dāng)斷開與服務(wù)器端的連接時(shí)發(fā)生
procedure TfrmClientMain.ClientSocketDisconnect(Sender: TObject;
Socket: TCustomWinSocket);
begin
  tbSend.Enabled := False;
  btnSend.Enabled := False;
  tbDisconnected.Enabled := False;
  StatusBar.Panels[0].Text := 已經(jīng)斷開與 + Socket.RemoteHost + 的連接;
end;

procedure TfrmClientMain.FormClose(Sender: TObject;
var Action: TCloseAction);
begin
  ClientSocket.Close ;
end;

//當(dāng)與服務(wù)器端的連接發(fā)生錯(cuò)誤時(shí)
procedure TfrmClientMain.ClientSocketError(Sender: TObject;
Socket: TCustomWinSocket; ErrorEvent: TErrorEvent;
var ErrorCode: Integer);
begin
  StatusBar.Panels[0].Text := 與服務(wù)器端的連接發(fā)生錯(cuò)誤;
  ErrorCode := 0;
end;

end.