c# - 将数据发送到 C++ Visual Studio 中的 tcp/端口

Question

我在 c# 中创建了两个应用程序服务器和客户端，它们都可以工作。我需要将客户端应用程序更改为 c++。这是我在 c# 中的代码:

            m_clientSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
            IPAddress ip = IPAddress.Parse("127.0.0.1");
            int iPortNo = System.Convert.ToInt16("5000");
            IPEndPoint ipEnd = new IPEndPoint(ip, iPortNo);
            m_clientSocket.Connect(ipEnd);
            if (m_clientSocket.Connected)
            {
                    byte[] packet = CreateMessage("salam");
                    if (m_clientSocket != null)
                    {
                        m_clientSocket.Send(packet);
                    } 

            }

效果很好，所以我用谷歌搜索了 c++ client code tcp 并找到了这个 URL

https://msdn.microsoft.com/en-us/library/windows/desktop/ms737591%28v=vs.85%29.aspx

这里是上面的url代码

#define WIN32_LEAN_AND_MEAN

#include <windows.h>
#include <winsock2.h>
#include <ws2tcpip.h>
#include <stdlib.h>
#include <stdio.h>


// Need to link with Ws2_32.lib, Mswsock.lib, and Advapi32.lib
#pragma comment (lib, "Ws2_32.lib")
#pragma comment (lib, "Mswsock.lib")
#pragma comment (lib, "AdvApi32.lib")


#define DEFAULT_BUFLEN 512
#define DEFAULT_PORT "27015"

int __cdecl main(int argc, char **argv)
{
    WSADATA wsaData;
    SOCKET ConnectSocket = INVALID_SOCKET;
    struct addrinfo *result = NULL,
        *ptr = NULL,
        hints;
    char *sendbuf = "this is a test";
    char recvbuf[DEFAULT_BUFLEN];
    int iResult;
    int recvbuflen = DEFAULT_BUFLEN;

    // Validate the parameters
    if (argc != 2) {
        printf("usage: %s server-name\n", argv[0]);
        return 1;
    }

    // Initialize Winsock
    iResult = WSAStartup(MAKEWORD(2, 2), &wsaData);
    if (iResult != 0) {
        printf("WSAStartup failed with error: %d\n", iResult);
        return 1;
    }

    ZeroMemory(&hints, sizeof(hints));
    hints.ai_family = AF_UNSPEC;
    hints.ai_socktype = SOCK_STREAM;
    hints.ai_protocol = IPPROTO_TCP;

    // Resolve the server address and port
    iResult = getaddrinfo(argv[1], DEFAULT_PORT, &hints, &result);
    if (iResult != 0) {
        printf("getaddrinfo failed with error: %d\n", iResult);
        WSACleanup();
        return 1;
    }

    // Attempt to connect to an address until one succeeds
    for (ptr = result; ptr != NULL; ptr = ptr->ai_next) {

        // Create a SOCKET for connecting to server
        ConnectSocket = socket(ptr->ai_family, ptr->ai_socktype,
            ptr->ai_protocol);
        if (ConnectSocket == INVALID_SOCKET) {
            printf("socket failed with error: %ld\n", WSAGetLastError());
            WSACleanup();
            return 1;
        }

        // Connect to server.
        iResult = connect(ConnectSocket, ptr->ai_addr, (int)ptr->ai_addrlen);
        if (iResult == SOCKET_ERROR) {
            closesocket(ConnectSocket);
            ConnectSocket = INVALID_SOCKET;
            continue;
        }
        break;
    }

    freeaddrinfo(result);

    if (ConnectSocket == INVALID_SOCKET) {
        printf("Unable to connect to server!\n");
        WSACleanup();
        return 1;
    }

    // Send an initial buffer
    iResult = send(ConnectSocket, sendbuf, (int)strlen(sendbuf), 0);
    if (iResult == SOCKET_ERROR) {
        printf("send failed with error: %d\n", WSAGetLastError());
        closesocket(ConnectSocket);
        WSACleanup();
        return 1;
    }

    printf("Bytes Sent: %ld\n", iResult);

    // shutdown the connection since no more data will be sent
    iResult = shutdown(ConnectSocket, SD_SEND);
    if (iResult == SOCKET_ERROR) {
        printf("shutdown failed with error: %d\n", WSAGetLastError());
        closesocket(ConnectSocket);
        WSACleanup();
        return 1;
    }

    // Receive until the peer closes the connection
    do {

        iResult = recv(ConnectSocket, recvbuf, recvbuflen, 0);
        if (iResult > 0)
            printf("Bytes received: %d\n", iResult);
        else if (iResult == 0)
            printf("Connection closed\n");
        else
            printf("recv failed with error: %d\n", WSAGetLastError());

    } while (iResult > 0);

    // cleanup
    closesocket(ConnectSocket);
    WSACleanup();

    return 0;
}

但问题是我不知道这段代码的哪些部分是 IP 和 Port？正如您在我的 c# 应用程序中看到的那样，我配置了 IP 和 port 。但是在 c++ 代码中我找不到任何变量来初始化 IP 和 Port

Answer 1

您的代码似乎循环遍历了最初由以下行设置的一系列可用端口:

iResult = getaddrinfo(argv[1], DEFAULT_PORT, &hints, &result);

&然后从这里循环

for (ptr = result; ptr != NULL; ptr = ptr->ai_next)

试图在这条线上建立连接

iResult = connect(ConnectSocket, ptr->ai_addr, (int)ptr->ai_addrlen);

IP 和端口值存储在 addrinfo 结构的 ai_addr 字段指向的结构中。 ai_addr 指向的结构依赖于协议(protocol)——对于 TCP，它是一个 sockaddr_in 结构，其中包含 sin_port & sin_addr，这是另一个 4 字节的 IP 地址结构。请参阅以下链接:

https://msdn.microsoft.com/en-gb/library/windows/desktop/ms737530(v=vs.85).aspx https://msdn.microsoft.com/en-gb/library/windows/desktop/ms740496(v=vs.85).aspx https://msdn.microsoft.com/en-us/library/windows/desktop/ms738571(v=vs.85).aspx