今天,我遇到了一個非常非常奇怪的問題。那是我的IDE始終無法識別包含last的最後一個類。我正在使用Qt Creator.My包括遵循:最後一個頭文件錯誤:C2065:'xxx':未聲明的標識符
#include "realtimemonitor.h"
#include "ui_realtimemonitor.h"
#include <QGraphicsView>
#include <QGraphicsScene>
#include <QHBoxLayout>
#include "forkliftinfo.h"
#include <thread>
#include "goodsitem.h"
#include "goodslocationitem.h"
#include "forkliftitem.h"
#include "chargingstationitem.h"
此時,IDE抱怨 「ChargingStationItem未聲明的標識符」。 如果我換forkliftitem.h與chargingstationitem.h,IDE會compain 「ForkliftItem未聲明的標識符」。我forkliftitem.h如下:
//forkliftitem.h
#ifndef CHARGINGSTATIONITEM_H
#define CHARGINGSTATIONITEM_H
#include <QGraphicsItem>
class ForkliftItem : public QGraphicsItem { public:
ForkliftItem();
};
#endif // CHARGINGSTATIONITEM_H
而且chargingstationitem.h:
//chargingstationitem.h
#ifndef CHARGINGSTATIONITEM_H
#define CHARGINGSTATIONITEM_H
#include <QGraphicsItem>
class ChargingStationItem : public QGraphicsItem { public:
ChargingStationItem();
};
#endif // CHARGINGSTATIONITEM_H
https://en.wikipedia.org/wiki/Include_guard – user4581301