delphi 判断端口(Port)是否被占用（转载）

  function IsPortUsed(aPort: Integer): Boolean;
  var
    _vSock: TSocket;
    _vWSAData: TWSAData;
    _vAddrIn: TSockAddrIn;
  begin
    Result := False;
    if WSAStartup(MAKEWORD(, ), _vWSAData) =  then
    begin
      _vSock := Socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
      try
        if _vSock <> SOCKET_ERROR then
        begin
          _vAddrIn.sin_family := AF_INET;
          _vAddrIn.sin_addr.S_addr := htonl(INADDR_ANY);
          _vAddrIn.sin_port := htons(aPort);
          if Bind(_vSock, _vAddrIn, SizeOf(_vAddrIn)) <>  then
            if WSAGetLastError = WSAEADDRINUSE then
              Result := True;
        end;
      finally
        CloseSocket(_vSock);
        WSACleanup();
      end;
    end;
  end;