c++ - 在其他地方访问时，C++类和对象变量似乎被覆盖

Question

这是我正在工作的CS项目。在设计完类之后，我遇到了一个问题，即某些变量在再次调用时会被覆盖。在特定情况下，我试图在构造时使int type = 1，但是稍后当我回想到函数外部的变量时，它会更改为6422216。我相当确定这是由于我对指针和地址，但我不确定如何找到它。
之前的时间变量存在类似的问题，但我设法使用Event * newEvent = new Event(事件构造函数参数)对其进行了修复，尽管我不确定为什么要对其进行修复。
主要功能起点:

GEL EventList = GEL(); // Where GEL is a class type that contains an event list
int main()
{
    //VarInit intializes all of the main variables
    VarInit();
    
    //REMEMBER: 0 = ARRIVAL TYPE, 1 = DEPARTURE TYPE
    //Class functions goes as such
    //EventList.Schedule(float Time, int Type, Packet NewPacket) where Packet is a separate packet class
    EventList.Schedule(GenArrivalTime(), 0, GenPacket());

    for(int i = 0; i < 1; i++)
    {
        //Example Gen Arrival Time
        
        Event CurrentEvent = Event(EventList.Remove());

        cout << "Current Event addr: " << &CurrentEvent << "\n";
        float CurrentTime = CurrentEvent.EventTime;
        cout << "CurrentEvent Time: " << CurrentTime << "\n";
        cout << "CurrentEvent Type: " << CurrentEvent.EventType << "\n";
        //Here the Type gets changed from 0 to 6422216
    }

类功能:

//I don't believe that there are any issues here
//When printing out the output it seems ok
void GEL::Schedule(float Time, int Type, Packet InsPacket)
{
    //create a new event called event with all of these arguments
    //Event(int _EventTime, Packet _ServicedPacket, int _EventType, Event* _NextEvent, Event * _PrevEvent);
    std::cout << "w/in GEL::Schedule EventTime = " << Time << "\n";
    std::cout << "w/in GEL::Schedule EventType = " << Type << "\n";
    //Type is OK here
    Event * NewEvent = new Event(Time, InsPacket, Type, NULL, NULL);
    //wow finally, all I had to do was insert the NEW keyword prolly because it doesn't change
    // insert that into the Insert function
    Insert(*NewEvent);
};

//I believe there might be an issue here, within the debugging print
//everything seems to be fine however afterwards it does change
Event GEL::Insert(Event NewEvent)
{
    if(FrontEventPtr == NULL)
    {
        //If there is nothing in the FrontEventPtr (head), then have the FrontEventPtr = NewEvent
        //Putting volatile as the packet seems to fix it here, but later breaks again in Remove()

        std::cout << "w/in GEL.Insert(): FrontEventPtr is NULL\n";

        //make the pointer point towards the new event
        FrontEventPtr = &NewEvent;

        std::cout << "w/in GEL::Insert() FrontEventPtr address: " << FrontEventPtr << "\n";
        std::cout << "w/in GEL.Insert(): FrontEventPtr -> EventTime = " << FrontEventPtr->EventTime << "\n";
        std::cout << "w/in GEL::Insert() EventType = " << FrontEventPtr->EventType << "\n";
        //hmmm for some reason EventType get's reassigned at this point

        return *FrontEventPtr;
    }

    //At this point FrontEventPtr contains something
    std::cout << "FrontEventPtr not null, setting a placeholder variable to store FrontEventPtr for further operations\n";
    Event* EventPlaceHolder = FrontEventPtr;

    if(EventPlaceHolder->EventTime > NewEvent.EventTime)
    {
        //If the current FrontEventPlaceholder is greater than the NewEvent Time, then set the new FrontEventPlaceholder equal to the NewEvent and swap items
        std::cout << "Swapping Items because old time is > new time\n";
        FrontEventPtr = &NewEvent;
        NewEvent.NextEvent = EventPlaceHolder;
        EventPlaceHolder->PrevEvent = &NewEvent;
        return NewEvent;
    }

    while((EventPlaceHolder->NextEvent != NULL) && (NewEvent.EventTime > EventPlaceHolder->NextEvent->EventTime))
    {
        //Keep swapping items until we find the right place to put the event
        EventPlaceHolder = EventPlaceHolder->NextEvent;
    }

    NewEvent.PrevEvent = EventPlaceHolder;
    NewEvent.NextEvent = EventPlaceHolder->NextEvent;
    EventPlaceHolder->NextEvent = &NewEvent;

    if(NewEvent.NextEvent != NULL)
    {
        NewEvent.NextEvent->PrevEvent = &NewEvent;
    }

    return NewEvent;
};

//The problem is very apparent here, it seems that the type variable changes here.
Event GEL::Remove()
{
    std::cout << "w/in GEL::Remove() FrontEventPtr address: " << FrontEventPtr << "\n";
    std::cout << "w/in GEL::Remove() FrontEventPtr -> EventTime = " << FrontEventPtr->EventTime << "\n";
    std::cout << "w/in GEL::Remove() EventType = " << FrontEventPtr->EventType << "\n";

    if(FrontEventPtr == NULL)
    {
        std::cout << "w/in GEL::Remove(), FrontEventPtr is null, returning *FrontEventPtr\n";
        return *FrontEventPtr;
    }

    std::cout << "w/in GEL::Remove(), FrontEventPtr != NULl\n";
    
    Event first_event = *FrontEventPtr;

    if(first_event.NextEvent != NULL)
    {
        first_event.NextEvent->PrevEvent = NULL;
    }

    FrontEventPtr = first_event.NextEvent;

    first_event.NextEvent = NULL;

    std::cout << "w/in GEL::Remove first_event.EventTime: " << first_event.EventTime << "\n";

    return first_event;
};

如果您需要更多信息，请告诉我。
这也是我第一次在stackOverflow上发帖，所以问问题时我不了解礼节，让我知道是否有不好的礼节。
感谢您抽出宝贵时间来帮助您

Answer 1

在您的Insert函数中，NewEvent不是指针而是一个值，这意味着当您调用Insert(* Event);时，它将创建一个副本，在Insert函数返回后，对象NewEvent被销毁。
我认为您应该将Insert签名更改为Insert(Event * NewEvent)