大家给这段程序解释下 ，这是什么思想啊
unit UnitTCPUDP;interface
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls,WinSock, ExtCtrls, ComCtrls,inifiles,StrUtils;
const
WM_SOCK = WM_USER + 82; {自定义windows消息}
//在tcp 服务器方式下,WM_SOCK为监听消息
// WM_SOCK+1到 WM_SOCK+MAX_ACCEPT 为与连接客户端进行通讯时的消息
MAX_ACCEPT=100;
FD_SET= MAX_ACCEPT;
type
TFormTCPUDP = class(TForm)
BtnSend: TButton;
MemoReceive: TMemo;
EditSend: TEdit;
Label2: TLabel;
Label3: TLabel;
Bevel2: TBevel;
STOpCode: TStaticText;
STIndex: TStaticText;
STCommand: TStaticText;
GroupBox1: TGroupBox;
GroupBox2: TGroupBox;
GroupBox3: TGroupBox;
RBTCP: TRadioButton;
RBUDP: TRadioButton;
Panel1: TPanel;
RBClient: TRadioButton;
RBServer: TRadioButton;
GroupBox4: TGroupBox;
BtnConnect: TButton;
BtnClose: TButton;
Bevel1: TBevel;
StatusBar1: TStatusBar;
PanelDest: TPanel;
Label4: TLabel;
EditRemoteHost: TEdit;
Label5: TLabel;
EditRemotePort: TEdit;
Label6: TLabel;
CmbSendTo: TComboBox;
Label7: TLabel;
PanelLocal: TPanel;
ChkBind: TCheckBox;
EditHostPort: TEdit;
Label1: TLabel;
procedure BtnSendClick(Sender: TObject);
procedure BtnConnectClick(Sender: TObject);
procedure RBTCPClick(Sender: TObject);
procedure RBUDPClick(Sender: TObject);
procedure BtnCloseClick(Sender: TObject);
procedure FormClose(Sender: TObject; var Action: TCloseAction);
procedure RBClientClick(Sender: TObject);
procedure RBServerClick(Sender: TObject);
procedure ChkBindClick(Sender: TObject);
procedure FormCreate(Sender: TObject);
procedure EditHostPortChange(Sender: TObject);
procedure EditRemoteHostChange(Sender: TObject);
procedure EditRemotePortChange(Sender: TObject);
procedure FormActivate(Sender: TObject);
procedure CmbSendToKeyPress(Sender: TObject; var Key: Char); {消息接送}
private
{ Private declarations }
FirstFlag:Boolean;
INIPath:String;
procedure ReadData(var Message: TMessage);
function ReadTCPUDPIni():boolean; //读取配置信息
procedure WriteIniStr(FileName:String;section:string;Ident:string;StringValue:string);//写系统信息
procedure WriteIniBool(FileName:String;section:string;Ident:string;BoolValue:Boolean);//写系统信息
protected
{ Protected declarations }
{ other fields and methods}
procedure wndproc(var message:Tmessage);override;
public
{ Public declarations }
end;
const
DATA_LENGTH =120; //数据长度
type
TUDPaction = packed record
opcode:byte; //操作码
index:word; //序列号
Command:byte; //命令字
data:array[0..(DATA_LENGTH-1)] of char; //数据
end;
var
FormTCPUDP: TFormTCPUDP;
AcceptSock:Array[0..MAX_ACCEPT] OF Tsocket;
FSockAccept : Array[0..MAX_ACCEPT] OF TSockAddrIn;
AcceptSockFlag: Array[0..MAX_ACCEPT] OF boolean;
AcceptNum:integer=0;
FSockLocal : TSockAddrIn;
PackageID:integer=0; //包序号
BindFlag:Boolean=true;
TcpFlag:Boolean=false;
ServerFlag:Boolean=false;
function WinSockInital(Handle: HWnd):bool;
Procedure WinSockClose();
implementation
{$R *.dfm}
{始化SOCKET}
function WinSockInital(Handle: HWnd):bool;
var TempWSAData: TWSAData;
i:integer;
begin
result := false;
{ 1 初始化SOCKET}
if WSAStartup(2, TempWSAData)=1 then //2表示启用winsock2
exit;
{若是用UDP通信，则用}
if TcpFlag then
AcceptSock[0]:=Socket(AF_INET,SOCK_STREAM,0)
else
AcceptSock[0]:=Socket(AF_INET,SOCK_DGRAM,0);
if AcceptSock[0]=SOCKET_ERROR then
exit;
if (BindFlag and not tcpflag) or (Serverflag and tcpflag) then
if bind(AcceptSock[0],FSockLocal,sizeof(FSockLocal))<>0 then
begin
WinSockClose();
exit;
end;
if Tcpflag then
if Serverflag then
begin
if Listen(AcceptSock[0],1)<>0 then //等待连接队列的最大长度为1
begin
WinSockClose();
exit;
end;
end
else
if connect(AcceptSock[0],FSockAccept[0],sizeof(FSockAccept[0]))<>0 then
begin
WinSockClose();
exit;
end;
{FD_READ 在读就绪的时候, 产生WM_SOCK 自定义消息号}
if not TcpFlag then
WSAAsyncSelect(AcceptSock[0], Handle , WM_SOCK, FD_READ)
else if Serverflag then
WSAAsyncSelect(AcceptSock[0], Handle , WM_SOCK, FD_READ or FD_ACCEPT or FD_CLOSE)
else
WSAAsyncSelect(AcceptSock[0], Handle , WM_SOCK, FD_READ or FD_CLOSE);
Result:=true;
end;
{关闭SOCKET}
Procedure WinSockClose();
var i:integer;
begin
for i:=1 to MAX_ACCEPT DO
if AcceptSockFlag[i] then
begin
CloseSocket(AcceptSock[i]);
AcceptSockFlag[i]:=false;
end;
CloseSocket(AcceptSock[0]); {closesocket函数用来关闭一个描述符为AcceptSock[0]套接字}
WSACleanup;
end;
function TFormTCPUDP.ReadTCPUDPIni():boolean;
var ti:TiniFile;
begin
ti:=TIniFile.Create(INIPath+'TCPUDP.ini');
EditHostPort.text:=ti.ReadString('Setting','LocalPort','');
ChkBind.Checked:=ti.ReadBool('Setting','BindStatus',false);
EditRemotePort.text:=ti.ReadString('Setting','RemotePort','');
EditRemoteHost.text:=ti.ReadString('Setting','RemoteHost','');
RBTCP.Checked:=ti.ReadBool('Setting','TCPStatus',false);
RBUDP.Checked:=not RBTCP.Checked;
RBServer.Checked:=ti.ReadBool('Setting','ServerStatus',false);
RBClient.Checked:=not RBServer.Checked;
end;
procedure TFormTCPUDP.WriteIniStr(FileName:String;Section:string;Ident:string;StringValue:string);
var ti:TiniFile;
begin
ti:=TIniFile.Create(FileName);
ti.writestring(section,Ident,StringValue);
ti.Free;
end;
procedure TFormTCPUDP.WriteIniBool(FileName:String;Section:string;Ident:string;BoolValue:Boolean);
var ti:TiniFile;
begin
ti:=TIniFile.Create(FileName);
ti.writebool(section,Ident,BoolValue);
ti.Free;
end;
procedure TFormTCPUDP.BtnSendClick(Sender: TObject);
var SEND_PACKAGE : TUDPaction; //数据发送
i:integer;
s:String;
begin //发送数据按钮
Fillchar(SEND_PACKAGE.data,Data_Length,chr(0));
SEND_PACKAGE.data[0]:='1';
SEND_PACKAGE.data[1]:='2';
SEND_PACKAGE.data[2]:='3';
SEND_PACKAGE.opcode:=2;
SEND_PACKAGE.index:=PackageID;
SEND_
s:=editsend.Text;
for i:=0 to length(EditSend.Text)-1 do
SEND_PACKAGE.data[i]:=s[i+1];
PackageID:=PackageID+1;
if not (Tcpflag and Serverflag) then
sendto(AcceptSock[0], SEND_PACKAGE,sizeof(SEND_PACKAGE), 0, FSockAccept[0], sizeof(FSockAccept[0]))
else if AcceptNum=0 then
Application.MessageBox('没有一个客户端和您建立连接','信息提示',MB_OK)
else
begin
i:=pos(' ',CmbSendto.Text);
if i>0 then
begin
i:=strtoint(MidStr(CmbSendTo.Text,8,i-8));
sendto(AcceptSock[i], SEND_PACKAGE,sizeof(SEND_PACKAGE), 0, FSockAccept[i], sizeof(FSockAccept[i]));
end
else
Application.MessageBox('您没有选择发送方','错误提示',MB_OK);
end;
// sendto(AcceptSock[0], NbtstatPacket,50, 0, FSockAccept[0], sizeof(FSockAccept[0]));
end;
procedure TFormTCPUDP.BtnConnectClick(Sender: TObject);
var s:String;
i:integer;
begin //连接按钮
s:='正在建立连接....';
StatusBar1.Panels[0].Text:=s;
Application.ProcessMessages;
FSockLocal.sin_family:=AF_INET;
FSockLocal.sin_port:=htons(strtoint(EditHostport.Text));
FSockAccept[0].sin_family:=AF_INET;
FSockAccept[0].sin_port:=htons(strtoint(EditRemoteport.Text));
FSockAccept[0].SIn_Addr.S_addr := inet_addr(PChar(EditRemoteHost.Text));//inet_addr(pchar(IP));
if WinSockInital(FormTCPUDP.Handle) then
begin
BtnConnect.Enabled:=false;
BtnClose.Enabled:=true;
BtnSend.Enabled:=true;
s:='连接成功！';
if ChkBind.Checked then
s:=s+', ---绑定端口';
if RBTcp.Checked then
begin
s:=s+',---TCP方式';
if RBServer.Checked then
s:=s+',---服务端'
else
s:=s+',---客户端';
end
else
s:=s+',---UDP方式';
if tcpflag and Serverflag then
begin
AcceptNum:=0;
CmbSendto.Clear;
StatusBar1.Panels[2].Text:='共有：'+inttostr(AcceptNum)+'个连接';
end;
end
else
begin
for i:=0 to StatusBar1.Panels.count-1 do
StatusBar1.Panels[i].Text:='';
s:='创建套接字失败!!';
end;
StatusBar1.Panels[0].Text:=s;
end;
procedure TFormTCPUDP.wndproc(var Message: TMessage);
begin
if (Message.Msg>=WM_SOCK) and (Message.Msg<=WM_SOCK+MAX_ACCEPT) then
ReadData(Message)
else
inherited wndproc(message);
end;
procedure TFormTCPUDP.ReadData(var Message: TMessage);
var
Receive_PACKAGE : TUDPaction; //数据发送
flen,len,i,index: integer;
Event: word;
begin
Index:=(Message.Msg-WM_SOCK);
flen:=sizeof(FSockAccept[Index]);
Event := WSAGetSelectEvent(Message.LParam);
if Event = FD_READ then
begin
len := recvfrom(AcceptSock[Index], Receive_PACKAGE, sizeof(Receive_PACKAGE), 0, FSockAccept[Index], Flen);
if len> 0 then
begin
StatusBar1.Panels[0].Text:='收到来自ip地址:'+inet_ntoa(FSockAccept[Index].sin_addr)+' 端口:'+inttostr(ntohs(FSockAccept[Index].sin_port))+'的数据';
StOpCode.Caption:= format('%.2d',[Receive_PACKAGE.opCode]);
StIndex.Caption:= format('%d',[Receive_PACKAGE.Index]);
StCommand.Caption:= format('%.2d',[Receive_]);
MemoReceive.Lines.Add(StrPas(Receive_PACKAGE.data))
end;
end
else if Event=FD_ACCEPT then
begin
for i:=1 to MAX_ACCEPT DO
if not AcceptSockFlag[i] then
begin
flen:=Sizeof(FSockAccept[i]);
AcceptSock[i]:=accept(AcceptSock[0],@FSockAccept[i],@flen);
WSAAsyncSelect(AcceptSock[i], Handle , WM_SOCK+i, FD_READ or FD_CLOSE);
AcceptSockFlag[i]:=true;
AcceptNum:=AcceptNum+1;
CmbSendto.Items.Add('套接口:'+inttostr(i)+' 地址:'+inet_ntoa(FSockAccept[i].sin_addr)+' 端口:'+inttostr(ntohs(FSockAccept[i].sin_port)));
break;
end;
StatusBar1.Panels[2].Text:='共有：'+inttostr(AcceptNum)+'个连接';
end
else if Event=FD_CLOSE then
begin
WSAAsyncSelect(AcceptSock[index], FormTCPUDP.Handle, 0, 0);
if index<>0 then
begin
for i:=0 to CmbSendto.Items.Count-1 do
if CmbSendto.Items.Strings[i]= '套接口:'+inttostr(index)+' 地址:'+inet_ntoa(FSockAccept[index].sin_addr)+' 端口:'+inttostr(ntohs(FSockAccept[index].sin_port)) then
begin
CmbSendto.Items.Delete(i);
break;
end;
CloseSocket(AcceptSock[index]);
AcceptSockFlag[index]:=false;
AcceptNum:=AcceptNum-1;
StatusBar1.Panels[2].Text:='共有：'+inttostr(AcceptNum)+'个连接';
end;
end;
end;
procedure TFormTCPUDP.RBTCPClick(Sender: TObject);
begin //tcp 方式按钮
writeiniBool(INIPath+'TCPUDP.ini','Setting','TCPStatus',true);
RBServer.Enabled:=true;
RBClient.Enabled:=true;
if RBServer.Checked then
begin
PanelDest.Visible:=false;
CmbSendto.Enabled:=true;
end
else
begin
PanelDest.Visible:=true;
PanelLocal.Visible:=false;
end;
ChkBind.Enabled:=false;
TcpFlag:=true;
end;
procedure TFormTCPUDP.RBUDPClick(Sender: TObject);
begin //UDP方式按钮
writeiniBool(INIPath+'TCPUDP.ini','Setting','TCPStatus',false);
RBServer.Enabled:=false;
RBClient.Enabled:=false;
PanelDest.Visible:=true;
TcpFlag:=false;
ChkBind.Enabled:=true;
CmbSendto.Enabled:=false;
PanelLocal.Visible:=true;
end;
procedure TFormTCPUDP.BtnCloseClick(Sender: TObject);
var i:integer;
begin //关闭按钮
WinSockClose();
BtnConnect.Enabled:=true;
BtnClose.Enabled:=false;
BtnSend.Enabled:=false;
CmbSendto.Clear;
for i:=0 to StatusBar1.Panels.count-1 do
StatusBar1.Panels[i].Text:='';
Statusbar1.Panels[0].Text:='已关闭套接字！！';
end;
procedure TFormTCPUDP.FormClose(Sender: TObject; var Action: TCloseAction);
begin
if BtnClose.Enabled then WinSockClose();
end;
procedure TFormTCPUDP.RBClientClick(Sender: TObject);
begin
writeiniBool(INIPath+'TCPUDP.ini','Setting','ServerStatus',false);
ServerFlag:=false;
PanelDest.Visible:=true;
CmbSendto.Enabled:=false;
if Tcpflag then
PanelLocal.Visible:=false
else
PanelLocal.Visible:=true;
end;
procedure TFormTCPUDP.RBServerClick(Sender: TObject);
begin //服务器端
writeiniBool(INIPath+'TCPUDP.ini','Setting','ServerStatus',true);
ServerFlag:=true;
if Tcpflag then
begin
PanelDest.Visible:=false;
CmbSendto.Enabled:=true;
ChkBind.Enabled:=false;
ChkBind.Checked:=true;
end
else
ChkBind.Enabled:=true;
PanelLocal.Visible:=true;
end;
procedure TFormTCPUDP.ChkBindClick(Sender: TObject);
begin //绑定按钮
writeiniBool(INIPath+'TCPUDP.ini','Setting','BindStatus',ChkBind.Checked);
BindFlag:=ChkBind.Checked;
end;
procedure TFormTCPUDP.FormCreate(Sender: TObject);
var i:integer;
begin
FirstFlag:=true;
for i:=1 to MAX_ACCEPT do
AcceptSockFlag[i]:=false;
INIPath:=extractFilePath(ParamStr(0));
end;
procedure TFormTCPUDP.EditHostPortChange(Sender: TObject);
begin //本地端口
writeiniStr(INIPath+'TCPUDP.ini','Setting','LocalPort',EditHostPort.Text);
end;
procedure TFormTCPUDP.EditRemoteHostChange(Sender: TObject);
begin //IP地址按钮
writeiniStr(INIPath+'TCPUDP.ini','Setting','RemoteHost',EditRemoteHost.Text);
end;
procedure TFormTCPUDP.EditRemotePortChange(Sender: TObject);
begin //目的端口
writeiniStr(INIPath+'TCPUDP.ini','Setting','RemotePort',EditRemotePort.Text);
end;
procedure TFormTCPUDP.FormActivate(Sender: TObject);
begin
if FirstFlag then
begin
FirstFlag:=false;
ReadTCPUDPIni();
end;
end;
procedure TFormTCPUDP.CmbSendToKeyPress(Sender: TObject; var Key: Char);
begin
key:=chr(0);
end;
end.
没看懂
