服务创建步骤

1. 设置服务入口函数ServiceMain,
   StartServiceCtrlDispatcher
2. 注册服务控制处理器，接收SCM的命令。
   RegisterServiceCtrlHandler
3. 服务执行，等待停止，反馈状态。

代码

#define SERVICE_NAME _T("MyXzmService")
#define LOGFILE _T("E:\\memstatus.txt")

SERVICE_STATUS ServiceStatus;
SERVICE_STATUS_HANDLE hStatus;

void WINAPI ServiceMain(int argc, char** argv);
void ControlHandler(DWORD request);
int WriteToLog(TCHAR *str);
int InitService();

// 文章： https://blog.csdn.net/nodeathphoenix/article/details/24181509
int APIENTRY _tWinMain(_In_ HINSTANCE hInstance,
                     _In_opt_ HINSTANCE hPrevInstance,
                     _In_ LPTSTR    lpCmdLine,
                     _In_ int       nCmdShow)
{
    UNREFERENCED_PARAMETER(hPrevInstance);
    UNREFERENCED_PARAMETER(lpCmdLine);
    OutputDebugString(_T("-------_tWinMain--------"));

    SERVICE_TABLE_ENTRY ServiceTable[2];
    ServiceTable[0].lpServiceName = SERVICE_NAME;   // 指向表示服务名称字符串的指针；当定义了多个服务时，那么这个域必须指定； 
    ServiceTable[0].lpServiceProc = (LPSERVICE_MAIN_FUNCTION)ServiceMain;               // 指向服务主函数的指针（服务入口点）； 

    ServiceTable[1].lpServiceName = NULL;
    ServiceTable[1].lpServiceProc = NULL;

    StartServiceCtrlDispatcher(ServiceTable);
    return 0;
}

// 该函数是服务的入口点。它运行在一个单独的线程当中，这个线程是由控制分派器创建的
void WINAPI ServiceMain(int argc, char** argv){
    OutputDebugString(_T("ServiceMain start"));
    ServiceStatus.dwServiceType = SERVICE_WIN32;            // 指示服务类型，创建 Win32 服务。赋值 SERVICE_WIN32 ； 
    ServiceStatus.dwCurrentState = SERVICE_START_PENDING;   // 指定服务的当前状态
    ServiceStatus.dwControlsAccepted = SERVICE_ACCEPT_STOP | SERVICE_ACCEPT_SHUTDOWN;   // 这个域通知 SCM 服务接受哪个域
    ServiceStatus.dwWin32ExitCode = 0;
    ServiceStatus.dwCheckPoint = 0;
    ServiceStatus.dwWaitHint = 0;

    // 为服务注册控制处理器,两个参数传递给此函数：服务名和指向 ControlHandlerfunction 的指针。 
    // 注册完控制处理器之后，获得状态句柄（hStatus）。通过调用 SetServiceStatus 函数，用 hStatus 向 SCM 报告服务的状态。 
    hStatus = RegisterServiceCtrlHandler(SERVICE_NAME, (LPHANDLER_FUNCTION)ControlHandler);
    if (hStatus == (SERVICE_STATUS_HANDLE)0)
    {
        // Registering Controll Handler failed;
        return;
    }
    OutputDebugString(_T("ServiceMain InitService"));
    int error = InitService();
    if (error)
    {
        OutputDebugString(_T("ServiceMain InitService fail."));
        // 初始化失败，终止服务
        ServiceStatus.dwCurrentState = SERVICE_STOPPED;
        ServiceStatus.dwWin32ExitCode = -1;
        SetServiceStatus(hStatus, &ServiceStatus);
        // 退出ServiceMan
        return;
    }
    ServiceStatus.dwCurrentState = SERVICE_RUNNING;
    SetServiceStatus(hStatus, &ServiceStatus);

    //  
    // 不断获取内存大小写入文件
    while (ServiceStatus.dwCurrentState == SERVICE_RUNNING)
    {
        TCHAR buffer[100];
        MEMORYSTATUS memory;
        GlobalMemoryStatus(&memory);
        _stprintf_s(buffer, _T("memory.dwAvailPhys=%d"), memory.dwAvailPhys);
        int result = WriteToLog(buffer);
        if (result)
        {
            ServiceStatus.dwCurrentState = SERVICE_STOPPED;
            ServiceStatus.dwWin32ExitCode = -1;
            SetServiceStatus(hStatus, &ServiceStatus);
            return;
        }

        // 等待10s
        Sleep(10000);
    }
}

void ControlHandler(DWORD request){
    switch (request)
    {
    case SERVICE_CONTROL_STOP:
        WriteToLog(_T("Monitoring stoppend."));
        ServiceStatus.dwCurrentState = SERVICE_STOPPED;
        ServiceStatus.dwWin32ExitCode = 0;
        SetServiceStatus(hStatus, &ServiceStatus);
        break;
    case SERVICE_CONTROL_SHUTDOWN:
        WriteToLog(_T("Monitoring shutdown."));
        ServiceStatus.dwCurrentState = SERVICE_STOPPED;
        ServiceStatus.dwWin32ExitCode = 0;
        SetServiceStatus(hStatus, &ServiceStatus);
        break;
    default:
        break;
    }
}

int InitService(){
    int result;
    result = WriteToLog(_T("Monitoring started."));
    return result;
}

int WriteToLog(TCHAR *str){
    FILE * log;
    _tfopen_s(&log, LOGFILE, _T("a+"));
    if (log == NULL)
    {
        return -1;
    }
    _ftprintf(log,_T("%s\n"), str);
    fclose(log);

    return 0;
}

SC.exe管理Service

sc命令的语法格式：

sc create MyService binpath= e:/xxx/MyService.exe ;创建服务MyService
sc start MyService ;启动服务
sc stop MyService ;停止服务
sc delete MyService ; 删除服务
sc config 服务名 start= auto|demand|disabled ;修改服务启动类型。start参数的值可以是demand（手动）、disabled（禁用），auto（自动）。

参考

C++编写Windows服务
https://blog.csdn.net/nodeathphoenix/article/details/24181509