unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, idContext, StdCtrls, IdCustomTCPServer, IdTCPServer, IdBaseComponent,
  IdComponent, IdTCPConnection, IdTCPClient;

type
  TForm1 = class(TForm)
    IdTCPClient1: TIdTCPClient;
    IdTCPServer1: TIdTCPServer;
    Edit1: TEdit;
    Edit2: TEdit;
    Label1: TLabel;
    Label2: TLabel;
    Edit3: TEdit;
    Button2: TButton;
    Label3: TLabel;
    ListBox1: TListBox;
    Edit4: TEdit;
    Button1: TButton;
    procedure Button1Click(Sender: TObject);
    procedure IdTCPServer1Execute(AContext: TIdContext);
    procedure Button2Click(Sender: TObject);
    procedure FormCreate(Sender: TObject);
  private
    { Private-Deklarationen }
  public
    { Public-Deklarationen }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);
begin
IdTCPServer1.Active:= False;
IdTCPServer1.DefaultPort:=StrToInt(Edit4.Text);
IdTCPServer1.Active:= True;
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
  with IdTCPClient1 do
    try
      Host := Edit1.Text;;
      Port := StrToInt(Edit2.Text);
      Connect;
      ShowMessage('Connected.');
      try
        IdTCPClient1.IOHandler.WriteLn(Edit3.Text);
        ShowMessage('Gesendet.');
      finally
      Disconnect;
      ShowMessage('Disconnected.');
      end;
    finally

    end;
end;



procedure TForm1.IdTCPServer1Execute(AContext: TIdContext);
begin
ListBox1.Items.Add(AContext.Connection.IOHandler.ReadLn);
end;