Winsock單客戶端服務器同時發送和接收

Question

我在C ++中使用簡單的Winsock聊天應用程序時遇到問題。 我編寫了一個代碼，使用戶可以選擇是否要發送數據或接收數據，並根據用戶的選擇，執行相應的功能。 我想要實現的是，用戶可以同時發送和接收數據。 我怎么能接近它？ 請注意，我不想使用多個客戶端，我只想通過服務器發送和接收數據，並同時通過客戶端發送和接收數據。

編輯：我添加了我的代碼。

#include <WinSock2.h>
#include <Windows.h>
#include <iostream>
#include <string>
#include <stdio.h>
#include <ctime>


int main()
{
    string IP;
    int userType;

    // Ask the user if he is server or client
    cout << "Hi, which type of user are you? 1 - Server, 2 - Client" <<endl;
    cin >> userType;

    // depending on the declared user type, execute the appropriate code
    if (userType == 1)
    {
        //initialize winsock and create a socket
        WSAData wsaData; // initialize
        iResult = WSAStartup(MAKEWORD(2,1), &wsaData);

        if (iResult != NO_ERROR) // check for errors
             cout << "Error at WSAStartup()" <<endl;
        else
             cout << "WSAStartup() is OK." <<endl;

        // create socket
        sockSocket = socket(AF_INET,SOCK_STREAM,IPPROTO_TCP); // create a socket
        if (sockSocket == INVALID_SOCKET) // check for errors
        {
            cout << "Error at socket(): " << WSAGetLastError();
            WSACleanup();
            return true;
        }
        else
            cout << "Socket() is OK." <<endl;
        return true;

        // bind to socket
        service.sin_addr.s_addr = inet_addr("0.0.0.0");
        service.sin_family = AF_INET;
        service.sin_port = htons(55555);

        if (bind(sockSocket, (SOCKADDR*)&service, sizeof(service)) == SOCKET_ERROR) // cheking for errors
        {
            cout << "Bind() failed." << endl;
            closesocket(sockSocket);
            return true;
        }
        else
            cout << "Bind() is OK." <<endl;


        // listen
        listen(sockSocket, SOMAXCONN);
        if (listen(sockSocket, 10) == SOCKET_ERROR) // check for errors
        {
            cout << "Error listening on socket." << endl;
            return true;
        }
        else
            cout << "Listen() is OK." <<endl;

        //accept connection
        servlen = sizeof(service);
        cout << "Waiting for user to connect..." << endl;

        acceptSocket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
        if(acceptSocket = accept(sockSocket, (SOCKADDR*)&service, &servlen))
        {
            cout << "A coonnection was found" <<endl<<endl;
        }
        sockSocket = acceptSocket;

        // receive messages
        do
        {
            std::string message;
            char Buffer[512];
            iResult = recv(sockSocket, Buffer, 512, 0);
            Buffer[iResult] = '\0';
            message = Buffer;
            currentDate();
            std::cout << Buffer <<endl<<endl;

        }while(iResult>0);

        closesocket(sockSocket);
        WSACleanup();
    }

    else if (userType == 2)
    {
        // exactly the same code as for server part to initialize and create socket

        // ask  for the ip the user wants to connect to
        cout << "Hi what's the IP that you want to connect to?" <<endl;
        cin >> IP;

        // connect to socket
        conService.sin_addr.s_addr = inet_addr(IP); // connect to the ipnuted IP
        conService.sin_family = AF_INET;
        conService.sin_port = htons(55555); // should the port also be the argument?

        if (connect(sockSocket, (SOCKADDR*)&conService, sizeof(conService)) == SOCKET_ERROR) // check for errors
        {
            cout << "Failed to connect: " << WSAGetLastError();
            WSACleanup();
            return true;
        }
        else
        {
            cout << "Connected." <<endl;
        }

        // send messages
        for (;;)
        {
            std::string message;
            std::getline(std::cin, message);
            unsigned int Length = strlen(message.c_str());
            if(Length>512)
                Length = 512;
            currentDate();
            iResult = send(sockSocket, message.c_str(),Length,0);
        }
        closesocket(sockSocket);
        WSACleanup();
    }

    WSACleanup();
    return 0;
}

Edit2：正如Lemy在評論中所建議的那樣，我需要有第二個線程（因為第一個線程就是主函數中正在發生的事情）。 根據我的理解，我可以使用CreateThread函數。 解決了如何發送和接收消息的問題（我應該創建另一個線程），但現在我遇到了實現解決方案的問題。 正如我在Lemy的回答下面的評論中所寫，我得到的錯誤是指我使用CreateThread函數的行（HANDLE hThread = CreateThread（0,0，＆ReadingThread，acceptSocket，0，＆dwThreadID）;）：

1. 從'SOCKET {aka unsigned int}'無效轉換為'PVOID {aka void *}'[-fpermissive] | 和
2. 從'DWORD {aka long unsigned int}'到'PDWORD {aka long unsigned int *}'的無效轉換[-fpermissive]

有什么提示嗎？ 希望這使我的問題更具體（如果不是請告訴我應該指定更多）。

Answer 1

您需要讓客戶端和服務器在后台連續讀取連接的生命周期，然后他們可以在需要時並行發送數據。 將您的閱讀邏輯移動到一個單獨的線程中，例如：

#include <WinSock2.h>
#include <Windows.h>
#include <iostream>
#include <string>
#include <stdio.h>
#include <ctime>

DWORD WINAPI ReadingThread(LPVOID param)
{
    SOCKET s = (SOCKET) param;
    char Buffer[512];
    int iResult;

    do
    {
        iResult = recv(s, Buffer, 512, 0);
        if (iResult <= 0) break;
        Buffer[iResult] = '\0';
        std::cout << "Recv: " << message << std::endl;
    }
    while (true);

    return 0;
}

int main()
{
    int userType;
    HANDLE hThread;
    DWORD dwThreadID;

    //initialize winsock and create a socket
    WSAData wsaData; // initialize
    iResult = WSAStartup(MAKEWORD(2,1), &wsaData);

    if (iResult != NO_ERROR) // check for errors
    {
        std::cout << "Error at WSAStartup()" << std::endl;
        return 0;
    }

    std::cout << "WSAStartup() is OK." << std::endl;

    // Ask the user if he is server or client
    std::cout << "Hi, which type of user are you? 1 - Server, 2 - Client" << std::endl;
    std::cin >> userType;

    // depending on the declared user type, execute the appropriate code
    if (userType == 1)
    {
        // create socket
        sockSocket = socket(AF_INET,SOCK_STREAM,IPPROTO_TCP); // create a socket
        if (sockSocket == INVALID_SOCKET) // check for errors
        {
            std::cout << "Error at socket(): " << WSAGetLastError() << std::endl;
            WSACleanup();
            return 0;
        }

        std::cout << "Socket() is OK." << std::endl;

        // bind to socket
        service.sin_addr.s_addr = INADDR_ANY;
        service.sin_family = AF_INET;
        service.sin_port = htons(55555);

        if (bind(sockSocket, (SOCKADDR*)&service, sizeof(service)) == SOCKET_ERROR) // cheking for errors
        {
            std::cout << "Error at bind(): " << WSAGetLastError() << std::endl;
            closesocket(sockSocket);
            WSACleanup();
            return 0;
        }

        std::cout << "Bind() is OK." << std::endl;

        // listen
        if (listen(sockSocket, 10) == SOCKET_ERROR) // check for errors
        {
            std::cout << "Error at listen(): " << WSAGetLastError() << std::endl;
            closesocket(sockSocket);
            WSACleanup();
            return 0;
        }

        std::cout << "Listen() is OK." << std::endl;

        //accept connection
        servlen = sizeof(service);
        std::cout << "Waiting for user to connect..." << std::endl;

        acceptSocket = accept(sockSocket, (SOCKADDR*)&service, &servlen);
        if (acceptSocket != INVALID_SOCKET)
        {
            std::cout << "Error at accept(): " << WSAGetLastError() << std::endl;
            closesocket(sockSocket);
            WSACleanup();
            return 0;
        }

        std::cout << "A client has connected" << std::endl << std::endl;

        // receive messages
        hThread = CreateThread(NULL, 0, &ReadingThread, (void*)acceptSocket, 0, &dwThreadID);
        if (!hThread)
        {
            std::cout << "Error at CreateThread(): " << GetLastError() << std::endl;
            closesocket(acceptSocket);
            closesocket(sockSocket);
            WSACleanup();
            return 0;
        }

        // send messages
        do
        {
            std::string message;
            if (!std::getline(std::cin, message))
                break;

            if (send(acceptSocket, msg.c_str(), msg.length(), 0) == SOCKET_ERROR)
            {
                std::cout << "Error at send(): " << WSAGetLastError() << std::endl;
                break;
            }
        }
        while (true);

        closesocket(acceptSocket);

        WaitForSingleObject(hThread, INFINITE);
        CloseHandle(hThread);

        closesocket(sockSocket);
        WSACleanup();
    }

    else if (userType == 2)
    {
        // create socket
        sockSocket = socket(AF_INET,SOCK_STREAM,IPPROTO_TCP); // create a socket
        if (sockSocket == INVALID_SOCKET) // check for errors
        {
            std::cout << "Error at socket(): " << WSAGetLastError() << std::endl;
            WSACleanup();
            return 0;
        }

        std::cout << "Socket() is OK." << std::endl;

        // ask  for the ip the user wants to connect to
        std::string IP;
        std::cout << "Hi what's the IP that you want to connect to?" << std::endl;
        std::cin >> IP;

        // connect to socket
        conService.sin_addr.s_addr = inet_addr(IP.c_str()); // connect to the ipnuted IP
        conService.sin_family = AF_INET;
        conService.sin_port = htons(55555); // should the port also be the argument?

        if (connect(sockSocket, (SOCKADDR*)&conService, sizeof(conService)) == SOCKET_ERROR) // check for errors
        {
            std::cout << "Failed to connect: " << WSAGetLastError() << std::endl;
            closesocket(sockSocket);
            WSACleanup();
            return 0;
        }

        std::cout << "Connected." << std::endl;

        // receive messages
        hThread = CreateThread(NULL, 0, &ReadingThread, (void*)sockSocket, 0, &dwThreadID);
        if (!hThread)
        {
            std::cout << "Error at CreateThread(): " << GetLastError() << std::endl;
            closesocket(sockSocket);
            WSACleanup();
            return 0;
        }

        // send messages
        do
        {
            std::string message;
            if (!std::getline(std::cin, message))
                break;

            if (send(sockSocket, msg.c_str(), msg.length(), 0) == SOCKET_ERROR)
            {
                std::cout << "Error at send(): " << WSAGetLastError() << std::endl;
                break;
            }
        }
        while (true);

        closesocket(sockSocket);

        WaitForSingleObject(hThread, INFINITE);
        CloseHandle(hThread);

        WSACleanup();
    }

    else
    {
        std::cout << "Invalid type entered!" << std::endl;
        WSACleanup();
        return 0;
    }

    return 0;
}