windows C++创建一个服务端类，ip为127.0.0.1 端口为7799，并分为.h和.cpp，并告诉我如何调用，我要全部完整的代码

在Windows上创建一个C++的服务端程序，通常会使用`WSAStartup`和`WSACleanup`初始化和清理Winsock库，以及`SOCKET`, `bind()`, `listen()`和`accept()`等网络函数来监听连接。下面是一个简单的例子，我们将创建一个名为`ServerService`的类，包含`.h`和`.cpp`两个文件。

**ServerService.h**

#pragma once
#include <winsock2.h>
#include <ws2tcpip.h>

class ServerService {
public:
    ServerService();
    ~ServerService();

    bool start(int port);
    void stop();

private:
    SOCKET serverSocket;
    sockaddr_in serverAddress;
};

**ServerService.cpp**

#include "ServerService.h"

ServerService::ServerService() {
    WSADATA wsaData;
    if (WSAStartup(MAKEWORD(2, 2), &wsaData) != 0) {
        std::cerr << "Error initializing Winsock." << std::endl;
        return;
    }
}

ServerService::~ServerService() {
    closesocket(serverSocket);
    WSACleanup();
}

bool ServerService::start(int port) {
    serverSocket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
    if (serverSocket == INVALID_SOCKET) {
        std::cerr << "Failed to create socket." << std::endl;
        return false;
    }

    serverAddress.sin_family = AF_INET;
    serverAddress.sin_addr.s_addr = htonl(INADDR_ANY); // Listen on all interfaces
    serverAddress.sin_port = htons(port);

    if (bind(serverSocket, (sockaddr*)&serverAddress, sizeof(serverAddress)) == SOCKET_ERROR) {
        std::cerr << "Failed to bind socket." << std::endl;
        closesocket(serverSocket);
        return false;
    }

    listen(serverSocket, SOMAXCONN); // Max connections

    std::cout << "Server started on port " << port << "." << std::endl;

    return true;
}

void ServerService::stop() {
    closesocket(serverSocket);
}

为了调用这个服务，你需要在主程序中实例化`ServerService`并启动它：

int main() {
    ServerService service;
    if (!service.start(7799)) {
        return -1;
    }

    try {
        // Wait for user to press a key or until the service is stopped manually
        MSG msg;
        while (GetMessage(&msg, nullptr, 0, 0)) {
            TranslateMessage(&msg);
            DispatchMessage(&msg);
        }
    } catch (...) {
        service.stop();
    }

    return 0;
}

在上述代码中，`main`函数会一直等待用户交互，直到停止服务。你可以通过关闭程序窗口来触发`stop()`函数。