zzunit.~pas

用Delphi开发语言实现的对网络链路层的连续ARQ协议的仿真。

unit zzUnit;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, ComCtrls, StdCtrls, ExtCtrls, Sockets, Spin;

type
  TForm1 = class(TForm)
    StatusBar1: TStatusBar;
    Memo2: TMemo;
    LabeledEdit1: TLabeledEdit;
    LabeledEdit2: TLabeledEdit;
    Button1: TButton;
    TcpServer1: TTcpServer;
    TcpClient1: TTcpClient;
    TcpClient2: TTcpClient;
    TcpServer2: TTcpServer;
    Timer1: TTimer;
    Timer2: TTimer;
    ListBox1: TListBox;
    SpinEdit1: TSpinEdit;
    Label1: TLabel;
    procedure TcpServer1Accept(Sender: TObject;
      ClientSocket: TCustomIpClient);
    procedure TcpServer2Accept(Sender: TObject;
      ClientSocket: TCustomIpClient);
    procedure FormCreate(Sender: TObject);
    procedure FormClose(Sender: TObject; var Action: TCloseAction);
    procedure sendinfo;
    procedure sendack;
    procedure Timer1Timer(Sender: TObject);
    procedure Timer2Timer(Sender: TObject);
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;
  InfoList,AckList:TStringList;
  info,acks:integer;
  showinfo,showack,infoerror,infolose:integer;
implementation

{$R *.dfm}
procedure TForm1.sendinfo;
var
  temp:string;
begin
  temp:=InfoList.Strings[info];
  randomize;
  if (random(infoerror-1)=0)and(infoerror>0) then
  temp:='1111111111111';     //这个代表错误帧
  TcpClient2.Connect;
  TcpClient2.Sendln(temp);
  TcpClient2.Disconnect;
  ListBox1.Selected[info]:=true;
  info:=info+1;
end;

procedure TForm1.sendack;
begin
  TcpClient1.Connect;
  TcpClient1.Sendln(AckList.Strings[acks]);
  TcpClient1.Disconnect;
  memo2.Lines.Append('已发送'+AckList.Strings[acks]);
  acks:=acks+1;
end;

procedure TForm1.TcpServer1Accept(Sender: TObject;
  ClientSocket: TCustomIpClient);  {收到信息帧}
begin
if Timer1.Enabled=false then Timer1.Enabled:=true;
  InfoList.Add(ClientSocket.Receiveln);
  ListBox1.Items.Add(InfoList.Strings[showinfo]);
  showinfo:=showinfo+1;
end;

procedure TForm1.TcpServer2Accept(Sender: TObject;
  ClientSocket: TCustomIpClient);    {收到监督帧}
begin
if Timer2.Enabled=false then Timer2.Enabled:=true;
  AckList.Add(ClientSocket.Receiveln);
  memo2.Lines.Append('已收到'+AckList.Strings[showack]);
  showack:=showack+1;
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
     InfoList:=TStringList.Create;
     AckList:=TStringList.Create;
     info:=0;
     acks:=0;
     showinfo:=0;
     showack:=0;
     TcpServer2.Active:=true;
     TcpServer1.Active:=true;
end;

procedure TForm1.FormClose(Sender: TObject; var Action: TCloseAction);
begin
     InfoList.Free;
     AckList.Free;
end;


procedure TForm1.Timer1Timer(Sender: TObject);
begin           //发送信息帧
     if info<InfoList.Count then
     sendinfo;
end;

procedure TForm1.Timer2Timer(Sender: TObject);
begin  //发送监督帧
     if acks<AckList.Count  then
     sendack;
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
    timer1.Interval:=spinedit1.Value*1000;
    timer2.Interval:=spinedit1.Value*1000;
    if LabeledEdit2.Text<>'0'then
    infoerror:=100 div strtoint(LabeledEdit2.Text)
    else  infoerror:=0;
    if  LabeledEdit1.Text<>'0'then
    infolose:=100 div strtoint(LabeledEdit1.Text)
    else  infolose:=0;
end;

end.