大家帮忙看看这段UDP通讯代码有什么错误，我无法收到数据啊！

[「已注销」]

TUdpSocket UP;

//---------------------------------------------------------------------------

#include <vcl.h>
#pragma hdrstop

#include "Unit1.h"
//---------------------------------------------------------------------------
#pragma package(smart_init)
#pragma resource "*.dfm"
TForm1 *Form1;
//---------------------------------------------------------------------------
__fastcall TForm1::TForm1(TComponent* Owner)
: TForm(Owner)
{
}
//---------------------------------------------------------------------------

void __fastcall TForm1::Button1Click(TObject *Sender)
{
UP->Open();
UP->Sendln("123","\r\n");
UP->Close();
}
//---------------------------------------------------------------------------

void __fastcall TForm1::UPConnect(TObject *Sender)
{
Edit1->Text ="Connect";
}
//---------------------------------------------------------------------------
void __fastcall TForm1::UPReceive(TObject *Sender, PChar Buf, int &DataLen)
{
Edit4->Text ="Rec";
}
//---------------------------------------------------------------------------
void __fastcall TForm1::UPSend(TObject *Sender, PChar Buf, int &DataLen)
{
Edit2->Text ="Send";
}
//---------------------------------------------------------------------------
void __fastcall TForm1::UPError(TObject *Sender, int SocketError)
{
Edit4->Text ="Err";
}
//---------------------------------------------------------------------------
void __fastcall TForm1::UPDisconnect(TObject *Sender)
{
Edit3->Text="DisConnect";
}
//---------------------------------------------------------------------------

[nickysoft]

什么东东，莫名其妙！！

[nuaawyd]

http://thecodes.home.sohu.com/data_0/multithreadudp_1.33.zip

[lg75]

me too

[greenyard]

应该到delphi组吧