用C++ builder编写查询端口被占用情况该怎么上手[再次提问]

用C++ builder编写查询端口被占用情况该如何下手[再次提问]
如题，上次一兄台提示用一个IdTCPServer组件，但是该组件发现端口被占用会弹出出错对话框，我不想出现这种状况。请问如何避免。另，还有其它轻量级的办法吗？我只是想查询端口是否被占用。
谢谢了！

[解决办法]

C/C++ code

#define PORT_INUSE    1    // 端口被占用#define PORT_FREE     2    // 端口未被占用#define PORT_ERROR    3    // 出错int TestPort(unsigned short usPort) {    // Create a SOCKET for listening for incoming connection requests    SOCKET ListenSocket;    ListenSocket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);    if (ListenSocket == INVALID_SOCKET)        return PORT_ERROR;    // The sockaddr_in structure specifies the address family,    // IP address, and port for the socket that is being bound.    sockaddr_in service;    service.sin_family = AF_INET;    service.sin_addr.s_addr = inet_addr("127.0.0.1");    service.sin_port = htons(usPort);    // Bind the socket.    int idResult;    if ( bind(ListenSocket, (SOCKADDR*)&service, sizeof(service)) == 0 )        idResult = PORT_FREE;    else if ( WSAGetLastError() == WSAEADDRINUSE )        idResult = PORT_INUSE;    else        idResult = PORT_ERROR;            closesocket(ListenSocket);    return idResult;}