参照网下做的indy简单TCP程序,为什么不行

参照网上做的indy简单TCP程序,为什么不行
本帖最后由 buynoo 于 2010-12-04 23:16:24 编辑教程网址:http://www.bianceng.cn/Programming/Delphi/200711/5436_3.htm

接下来是代码可能大家都做过我也基本是复制粘贴的就申明了几个过程/变量而已居然还会出错

客户端:

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls, IdAntiFreezeBase, IdAntiFreeze, IdBaseComponent,
  IdComponent, IdTCPConnection, IdTCPClient;

type
  TFormMain = class(TForm)
    IdTCPClient: TIdTCPClient;
    IdAntiFreeze: TIdAntiFreeze;
    EdtHost: TEdit;
    EdtPort: TEdit;
    Label1: TLabel;
    Label2: TLabel;
    Label3: TLabel;
    EdtData: TEdit;
    LbLog: TListBox;
    BtnConnect: TButton;
    BtnSend: TButton;
    BtnDisconnect: TButton;
    Label4: TLabel;
    procedure BtnConnectClick(Sender: TObject);
    procedure BtnSendClick(Sender: TObject);
    procedure BtnDisconnectClick(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  FormMain: TFormMain;

implementation

{$R *.dfm}
//连接
procedure TFormMain.BtnConnectClick(Sender: TObject);
begin
  IdTCPClient.Host := EdtHost.Text;
  IdTCPClient.Port := StrToInt(EdtPort.Text);
  LbLog.Items.Add('正在连接 ' + EdtHost.Text + '...');
  with IdTCPClient do
  begin
    try
      Connect(5000);
      try
      LbLog.Items.Add(ReadLn());
      BtnConnect.Enabled := False;
      BtnSend.Enabled := True;
      BtnDisconnect.Enabled := True;
      except
      LbLog.Items.Add('远程主机无响应！');
      IdTCPClient.Disconnect();
      end;//end try
    except
    LbLog.Items.Add('无法建立到' + EdtHost.Text + '的连接！');
    end;//end try
  end;//end with
end;

//发送数据
procedure TFormMain.BtnSendClick(Sender: TObject);
begin
LbLog.Items.Add('DATA ' + EdtData.Text);
with IdTCPClient do
begin
try
WriteLn('DATA ' + EdtData.Text);
LbLog.Items.Add(ReadLn())
except
LbLog.Items.Add('发送数据失败！');
IdTCPClient.Disconnect();
LbLog.Items.Add('同主机 ' + EdtHost.Text + ' 的连接已断开！');
BtnConnect.Enabled := True;
BtnSend.Enabled := False;
BtnDisconnect.Enabled := False;
end;//end try
end;//end with
end; 
 

//断开连接
procedure TFormMain.BtnDisconnectClick(Sender: TObject);
var
Received: string;
begin
LbLog.Items.Add('QUIT');
try
IdTCPClient.WriteLn('QUIT');
finally
IdTCPClient.Disconnect();
LbLog.Items.Add('同主机 ' + EdtHost.Text + ' 的连接已断开！');
BtnConnect.Enabled := True;
BtnSend.Enabled := False;
BtnDisconnect.Enabled := False;
end;//end try
end;

end.

服务端:

unit Unit2;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls, IdBaseComponent, IdComponent, IdTCPServer, StrUtils;

type
  TFormMain = class(TForm)
    Label1: TLabel;
    EdtPort: TEdit;
    Label2: TLabel;
    EdtData: TEdit;
    Label3: TLabel;
    LbLog: TListBox;
    BtnStart: TButton;
    BtnStop: TButton;
    IdTCPServer: TIdTCPServer;
    procedure BtnStartClick(Sender: TObject);
    procedure BtnStopClick(Sender: TObject);
    procedure IdTCPServerConnect(AThread: TIdPeerThread);
    procedure IdTCPServerExecute(AThread: TIdPeerThread);
    procedure DisplayData();
    procedure AddLogEntry();

  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  FormMain: TFormMain;
  FLogEntry: string;
  FReceived: string;

implementation

{$R *.dfm}

procedure TFormMain.BtnStartClick(Sender: TObject);
begin
  IdTCPServer.DefaultPort := StrToInt(EdtPort.Text);           //获取端口值
  IdTCPServer.Active := True;                                  //启用IdTCPServer
  BtnStart.Enabled := False;
  BtnStop.Enabled := True;
  LbLog.Items.Add('服务器已成功启动！');
end;

procedure TFormMain.BtnStopClick(Sender: TObject);
begin
  IdTCPServer.Active := False;                                  //不启用
  BtnStart.Enabled := True;
  BtnStop.Enabled := False;
  LbLog.Items.Add('服务器已成功停止！');
end;


procedure TFormMain.IdTCPServerConnect(AThread: TIdPeerThread); //被连接
begin
  LbLog.Items.Add('来自主机 '
  + AThread.Connection.Socket.Binding.PeerIP
  + ' 的连接请求已被接纳！');
  AThread.Connection.WriteLn('100: 欢迎连接到TCP服务器！');
end;


procedure TFormMain.IdTCPServerExecute(AThread: TIdPeerThread);
var
sCommand: string;
begin
  with AThread.Connection do 
 
  begin
    sCommand := ReadLn();
    FLogEntry := sCommand + ' 来自于主机 '
    + AThread.Connection.Socket.Binding.PeerIP;
    AThread.Synchronize(AddLogEntry);
  if AnsiStartsText('DATA ', sCommand) then
  begin
    FReceived := RightStr(sCommand, Length(sCommand)-5);
    WriteLn('200: 数据接收成功！');
    AThread.Synchronize(DisplayData);
  end
  else if SameText(sCommand, 'QUIT') then begin
    FLogEntry := '断开同主机 '
    + AThread.Connection.Socket.Binding.PeerIP
    + ' 的连接！';
    AThread.Synchronize(AddLogEntry);
    Disconnect;
  end
  else begin
    WriteLn('500: 无法识别的命令！');
    FLogEntry := '无法识别命令：' + sCommand;
    AThread.Synchronize(AddLogEntry);
  end;//endif
end;
end;


procedure TFormMain.DisplayData();
begin
  EdtData.Text := FReceived;
end;

procedure TFormMain.AddLogEntry();
begin
  LbLog.Items.Add(FLogEntry);
end;

end.

连上去是远程主机无响应！郁闷
[解决办法]


      try
      LbLog.Items.Add(ReadLn());
      BtnConnect.Enabled := False;
      BtnSend.Enabled := True;
      BtnDisconnect.Enabled := True;
      except
      LbLog.Items.Add('远程主机无响应！');
      IdTCPClient.Disconnect();
      end;

既然提示无响应，那就出在这段代码中，ReadLn是什么，你在这个代码段设置断点，调试一下吧，估计是ReadLn出错
[解决办法]
由于是复制的，button没有事件

参照网下做的indy简单TCP程序,为什么不

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