c++ - 无法使用 UDP 套接字 c++ 收听

Question

我正在尝试为服务器 C++ 文件实现 UDP 套接字。我有以下代码来设置套接字

//Create the server socket
    if ((s = socket(AF_INET, SOCK_DGRAM, 0)) == INVALID_SOCKET)
        throw "can't initialize socket";


    //Fill-in Server Port and Address info.
    sa.sin_family = AF_INET;
    sa.sin_port = htons(port);
    sa.sin_addr.s_addr = htonl(INADDR_ANY);


    //Bind the server port

    if (bind(s, (LPSOCKADDR)&sa, sizeof(sa)) == SOCKET_ERROR)
        throw "can't bind the socket";
    cout << "Bind was successful" << endl;

    //Successfull bind, now listen for client requests.

    if (listen(s, 10) == SOCKET_ERROR)
        throw "couldn't  set up listen on socket";
    else cout << "Listen was successful" << endl
            << "Waiting to be contacted for transferring files..." << endl;

运行此代码时，我到达最后一个 if 语句，出现 SOCKET_ERROR，抛出“无法在套接字上设置监听”。当我将其作为 TCP 连接(如下所示)时，一切都设置正确:

 if ((s = socket(AF_INET, SOCK_STREAM, 0)) == INVALID_SOCKET)
        throw "can't initialize socket";

将 SOCK_STREAM 更改为 SOCK_DGRAM 会给我这个错误。有谁知道这里可能是什么问题？

Answer 1

你不能监听 UDP 套接字。请参阅文档:

The sockfd argument is a file descriptor that refers to a socket of type SOCK_STREAM or SOCK_SEQPACKET.