unit Unit1;

{$mode objfpc}{$H+}

interface

uses
  Classes, SysUtils, Forms, Controls, Graphics, Dialogs, StdCtrls, IdUDPServer,
  IdUDPClient, IdSocketHandle, IdGlobal;

type

  { TForm1 }

  TForm1 = class(TForm)
    Button1: TButton;
    Edit1: TEdit;
    IdUDPClient1: TIdUDPClient;
    IdUDPServer1: TIdUDPServer;
    Memo1: TMemo;
    procedure Button1Click(Sender: TObject);
    procedure IdUDPServer1UDPRead(AThread: TIdUDPListenerThread;
      const AData: TIdBytes; ABinding: TIdSocketHandle);
  private

  public

  end;

var
  Form1: TForm1;
  Msg: string;

implementation

{$R *.lfm}

{ TForm1 }



procedure TForm1.Button1Click(Sender: TObject);
begin
  IdUDPClient1.Send(Edit1.Text);
  Memo1.Lines.Add('You: ' + Edit1.Text);
  Edit1.Clear;
end;

procedure TForm1.IdUDPServer1UDPRead(AThread: TIdUDPListenerThread;
  const AData: TIdBytes; ABinding: TIdSocketHandle);
begin
  if BytesToString(AData) <> 'Hello' then begin
    ABinding.SendTo(ABinding.PeerIP, ABinding.PeerPort, ToBytes(Byte(0)));
  end;
  Memo1.Lines.Add(ToHex(AData));
  Memo1.Lines.Add('ser>>'+BytesToString(AData));

  //Memo1.GoToTextEnd;
end;

end.