delphi 7 TServerSocket和TClientSocket两个组件

笔者在工作中遇到对局域网中各工作站与服务器之间进行Socket通信的问题。现在将本人总结出来的TServerSocket和TClientSocket两个组件的基本用法写出来，希望与您分享。 

ClientSocket组件为客户端组件。它是通信的请求方，也就是说，它是主动地与服务器端建立连接。 

ServerSocket组件为服务器端组件。它是通信的响应方，也就是说，它的动作是监听以及被动接受客户端的连接请求，并对请求进行回复。 

ServerSocket组件可以同时接受一个或多个ClientSocket组件的连接请求，并与每个ClientSocket组件建立单独的连接，进行单独的通信。因此，一个服务器端可以为多个客户端服务。 

设计思路 

本例包括一个服务器端程序和一个客户端程序。客户端程序可以放到多个计算机上运行，同时与服务器端进行连接通信。 

本例的重点，一是演示客户端与服务器端如何通信；二是当有多个客户端同时连接到服务器端时，服务器端如何识别每个客户端，并对请求给出相应的回复。为了保证一个客户端断开连接时不影响其它客户端与服务器端的通信，同时保证服务器端能够正确回复客户端的请求，在本例中声明了一个记录类型： 

type 

client_record=record 

CHandle: integer; //客户端套接字句柄 

CSocket:TCustomWinSocket; //客户端套接字 

CName:string; //客户端计算机名称 

CAddress:string; //客户端计算机IP地址 

CUsed: boolean; //客户端联机标志 

end; 

利用这个记录类型数据保存客户端的信息，同时保存当前客户端的连接状态。其中，CHandle保存客户端套接字句柄，以便准确定位每个与服务器端保持连接的客户端；Csocket保存客户端套接字，通过它可以对客户端进行回复。Cused记录当前客户端是否与服务器端保持连接。 

下面对组件ServerSocket和ClientSocket的属性设置简单说明

ServerSocket的属性： 

· Port，是通信的端口，必须设置。在本例中设置为1025； 

· ServerTypt，服务器端读写信息类型，设置为stNonBlocking表示异步读写信息，本例中采用这种方式。 

· ThreadCacheSize，客户端的最大连接数，就是服务器端最多允许多少客户端同时连接。本例采用默认值10。 

其它属性采用默认设置即可。 

ClientSocket的属性： 

· Port，是通信的端口，必须与服务器端的设置相同。在本例中设置为1025； 

· ClientType，客户端读写信息类型，应该与服务器端的设置相同，为stNonBlocking表示异步读写信息。 

· Host，客户端要连接的服务器的IP地址。必须设置，当然也可以在代码中动态设置。 

其它属性采用默认设置即可。 

程序源代码: 

· 服务器端源码（uServerMain.pas）： 

unit uServerMain; 

interface 

uses 

Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs, 

ScktComp, ToolWin, ComCtrls, ExtCtrls, StdCtrls, Buttons; 

const 

CMax=10; //客户端最大连接数 

type 

client_record=record 

CHandle: integer; //客户端套接字句柄 

CSocket:TCustomWinSocket; //客户端套接字 

CName:string; //客户端计算机名称 

CAddress:string; //客户端计算机IP地址 

CUsed: boolean; //客户端联机标志 

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; //客户端连接数组 

Sessions: integer; //客户端连接数 

end; 

var 

frmServerMain: TfrmServerMain; 

implementation 

{$R *.DFM} 

//打开套接字连接，并使套接字进入监听状态 

procedure TfrmServerMain.tbConnectClick(Sender: TObject); 

begin 

ServerSocket.Open ; 

end; 

//关闭套接字连接，不再监听客户端的请求 

procedure TfrmServerMain.tbDisconnectedClick(Sender: TObject); 

begin 

ServerSocket.Close; 

StatusBar.Panels[0].Text :='服务器套接字连接已经关闭，无法接受客户端的连接请求.'; 

end; 

//从客户端读取信息 

procedure TfrmServerMain.ServerSocketClientRead(Sender: TObject; 

Socket: TCustomWinSocket); 

var 

i:integer; 

begin 

//将从客户端读取的信息添加到Memo1中 

Memo1.Lines.Add(Socket.ReceiveText); 

for i:=0 to sessions do 

begin 

//取得匹配的客户端 

if session[i].CHandle = Socket.SocketHandle then 

begin 

session[i].CSocket.SendText('回复客户端'+session[i].CAddress+' ==> '+Edit1.Text); 

end; 

end; 

end; 

//服务器端套接字进入监听状态，以便监听客户端的连接 

procedure TfrmServerMain.ServerSocketListen(Sender: TObject; 

Socket: TCustomWinSocket); 

begin 

StatusBar.Panels[0].Text :='等待客户端连接...'; 

end; 

//当客户端连接到服务器端以后 

procedure TfrmServerMain.ServerSocketClientConnect(Sender: TObject; 

Socket: TCustomWinSocket); 

var 

i,j:integer; 

begin 

j:=-1; 

for i:=0 to sessions do 

begin 

//在原有的客户端连接数组中有中断的客户端连接 

if not session[i].CUsed then 

begin 

session[i].CHandle := Socket.SocketHandle ;//客户端套接字句柄 

session[i].CSocket := Socket; //客户端套接字 

session[i].CName := Socket.RemoteHost ; //客户端计算机名称 

session[i].CAddress := Socket.RemoteAddress ;//客户端计算机IP 

session[i].CUsed := True; //连接数组当前位置已经占用 

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 := '客户端 '+Socket.RemoteHost + ' 已经连接'; 

end; 

//当客户端断开连接时 

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 :='客户端 '+Socket.RemoteHost + ' 已经断开'; 

end; 

//关闭窗口 

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; 

//当客户端正在与服务器端连接时 

procedure TfrmServerMain.ServerSocketGetSocket(Sender: TObject; 

Socket: Integer; var ClientSocket: TServerClientWinSocket); 

begin 

StatusBar.Panels[0].Text :='客户端正在连接...'; 

end; 

//客户端发生错误 

procedure TfrmServerMain.ServerSocketClientError(Sender: TObject; 

Socket: TCustomWinSocket; ErrorEvent: TErrorEvent; 

var ErrorCode: Integer); 

begin 

StatusBar.Panels[0].Text :='客户端'+Socket.RemoteHost +'发生错误！'; 

ErrorCode := 0; 

end; 

end. 

· 客户端源码(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'; //服务器端地址 

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} 

//打开套接字连接 

procedure TfrmClientMain.tbConnectedClick(Sender: TObject); 

begin 

ClientSocket.Open ; 

end; 

//关闭套接字连接 

procedure TfrmClientMain.tbDisconnectedClick(Sender: TObject); 

begin 

ClientSocket.Close; 

end; 

//接受服务器端的回复 

procedure TfrmClientMain.ClientSocketRead(Sender: TObject; 

Socket: TCustomWinSocket); 

begin 

Memo1.Lines.Add(Socket.ReceiveText); 

end; 

//发送信息到服务器端 

procedure TfrmClientMain.tbSendClick(Sender: TObject); 

begin 

ClientSocket.Socket.SendText(Edit1.Text); 

end; 

procedure TfrmClientMain.tbCloseClick(Sender: TObject); 

begin 

Close; 

end; 

//设置要连接的服务器端地址 

procedure TfrmClientMain.FormShow(Sender: TObject); 

begin 

ClientSocket.Host := SocketHost; 

end; 

//已经连接到服务器端 

procedure TfrmClientMain.ClientSocketConnect(Sender: TObject; 

Socket: TCustomWinSocket); 

begin 

tbSend.Enabled := True; 

tbDisconnected.Enabled :=True; 

btnSend.Enabled := True; 

StatusBar.Panels[0].Text := '已经连接到 '+ Socket.RemoteHost ; 

end; 

//正在连接到服务器端 

procedure TfrmClientMain.ClientSocketConnecting(Sender: TObject; 

Socket: TCustomWinSocket); 

begin 

StatusBar.Panels[0].Text := '正在连接到服务器... ' ; 

end; 

//当断开与服务器端的连接时发生 

procedure TfrmClientMain.ClientSocketDisconnect(Sender: TObject; 

Socket: TCustomWinSocket); 

begin 

tbSend.Enabled := False; 

btnSend.Enabled := False; 

tbDisconnected.Enabled := False; 

StatusBar.Panels[0].Text := '已经断开与 '+ Socket.RemoteHost +' 的连接'; 

end; 

procedure TfrmClientMain.FormClose(Sender: TObject; 

var Action: TCloseAction); 

begin 

ClientSocket.Close ; 

end; 

//当与服务器端的连接发生错误时 

procedure TfrmClientMain.ClientSocketError(Sender: TObject; 

Socket: TCustomWinSocket; ErrorEvent: TErrorEvent; 

var ErrorCode: Integer); 

begin 

StatusBar.Panels[0].Text := '与服务器端的连接发生错误'; 

ErrorCode := 0; 

end; 

end. 

小结 

上述方法是比较简单的实现方法，同时也是相对较容易理解的方法。通过这个方法，笔者成功实现了局域网内多个客户端与服务器端进行Socket通信的功能，同时可以保证一个客户端的连接、通信或是断开都不影响其它客户端的正常通信。 

附录： 

服务器端窗体和客户端窗体及组件的属性设置参加相应的DFM文件。 

uServerMain.pas对应的DFM文件(uServerMain.dfm) 

object frmServerMain: TfrmServerMain 

Left = 297 

Top = 258 

BorderIcons = [biSystemMenu, biMinimize] 

BorderStyle = bsSingle 

Caption = 'ServerSocket' 

ClientHeight = 279 

ClientWidth = 476 

Color = clBtnFace 

Font.Charset = DEFAULT_CHARSET 

Font.Color = clWindowText 

Font.Height = -11 

Font.Name = 'MS Sans Serif' 

Font.Style = [] 

OldCreateOrder = False 

OnClose = FormClose 

OnCreate = FormCreate 

PixelsPerInch = 96 

TextHeight = 13 

object ControlBar1: TControlBar 

Left = 0 

Top = 0 

Width = 476 

Height = 30 

Align = alTop 

AutoSize = True 

TabOrder = 0 

object ToolBar1: TToolBar 

Left = 11 

Top = 2 

Width = 459 

Height = 22 

ButtonHeight = 21 

ButtonWidth = 55 

Caption = 'ToolBar1' 

EdgeInner = esNone 

EdgeOuter = esNone 

Flat = True 

ShowCaptions = True 

TabOrder = 0 

object tbConnect: TToolButton 

Left = 0 

Top = 0 

Caption = ' 连接 ' 

ImageIndex = 0 

OnClick = tbConnectClick 

end 

object tbDisconnected: TToolButton 

Left = 55 

Top = 0 

Caption = '断开' 

ImageIndex = 4 

OnClick = tbDisconnectedClick 

end 

object tbClose: TToolButton 

Left = 110 

Top = 0 

Caption = '关闭' 

ImageIndex = 3 

OnClick = tbCloseClick 

end 

end 

end 

object Edit1: TEdit 

Left = 0 

Top = 232 

Width = 473 

Height = 21 

TabOrder = 1 

Text = '你好！' 

end 

object Memo1: TMemo 

Left = 0 

Top = 30 

Width = 476 

Height = 195 

Align = alTop 

TabOrder = 2 

end 

object StatusBar: TStatusBar 

Left = 0 

Top = 257 

Width = 476 

Height = 22 

Panels = < 

item 

Width = 50 

end> 

SimplePanel = False 

end 

object ServerSocket: TServerSocket 

Active = False 

Port = 1025 

ServerType = stNonBlocking 

OnListen = ServerSocketListen 

OnGetSocket = ServerSocketGetSocket 

OnClientConnect = ServerSocketClientConnect 

OnClientDisconnect = ServerSocketClientDisconnect 

OnClientRead = ServerSocketClientRead 

OnClientError = ServerSocketClientError 

Left = 368 

end 

end 

uClientMain.pas对应的DFM文件(uClientMain.dfm) 

object frmClientMain: TfrmClientMain 

Left = 361 

Top = 290 

BorderIcons = [biSystemMenu, biMinimize] 

BorderStyle = bsSingle 

Caption = 'ClientSocket' 

ClientHeight = 230 

ClientWidth = 402 

Color = clBtnFace 

Font.Charset = DEFAULT_CHARSET 

Font.Color = clWindowText 

Font.Height = -11 

Font.Name = 'MS Sans Serif' 

Font.Style = [] 

OldCreateOrder = False 

Position = poScreenCenter 

OnClose = FormClose 

OnShow = FormShow 

PixelsPerInch = 96 

TextHeight = 13 

object ControlBar1: TControlBar 

Left = 0 

Top = 0 

Width = 402 

Height = 30 

Align = alTop 

AutoSize = True 

TabOrder = 0 

object ToolBar1: TToolBar 

Left = 11 

Top = 2 

Width = 385 

Height = 22 

ButtonHeight = 21 

ButtonWidth = 55 

Caption = 'ToolBar1' 

EdgeInner = esNone 

EdgeOuter = esNone 

Flat = True 

ShowCaptions = True 

TabOrder = 0 

object tbConnected: TToolButton 

Left = 0 

Top = 0 

Caption = ' 连接 ' 

ImageIndex = 0 

OnClick = tbConnectedClick 

end 

object tbSend: TToolButton 

Left = 55 

Top = 0 

Caption = '发送' 

Enabled = False 

ImageIndex = 1 

OnClick = tbSendClick 

end 

object tbDisconnected: TToolButton 

Left = 110 

Top = 0 

Caption = '断开' 

Enabled = False 

ImageIndex = 3 

OnClick = tbDisconnectedClick 

end 

object tbClose: TToolButton 

Left = 165 

Top = 0 

Caption = '退出' 

ImageIndex = 2 

OnClick = tbCloseClick 

end 

end 

end 

object Edit1: TEdit 

Left = 0 

Top = 184 

Width = 321 

Height = 21 

TabOrder = 1 

Text = '问候' 

end 

object Memo1: TMemo 

Left = 0 

Top = 30 

Width = 402 

Height = 147 

Align = alTop 

TabOrder = 2 

end 

object StatusBar: TStatusBar 

Left = 0 

Top = 208 

Width = 402 

Height = 22 

Panels = < 

item 

Width = 50 

end> 

SimplePanel = False 

end 

object btnSend: TBitBtn 

Left = 336 

Top = 183 

Width = 60 

Height = 22 

Caption = '发送' 

Enabled = False 

TabOrder = 4 

OnClick = tbSendClick 

end 

object ClientSocket: TClientSocket 

Active = False 

ClientType = ctNonBlocking 

Port = 1025 

OnConnecting = ClientSocketConnecting 

OnConnect = ClientSocketConnect 

OnDisconnect = ClientSocketDisconnect 

OnRead = ClientSocketRead 

OnError = ClientSocketError 

Left = 320 

end 

end