Qt 4.7找不到符号错误

Question

任何人都可以向我解释这个错误吗？它好像它是与MOC发生的错误：

Undefined symbols: 
make: Leaving directory `/Users/Dylan/Documents/programming/qt/Clock-build-desktop' 
    "ClockDelegate::ClockDelegate(QObject*)", referenced from: 
     AnalogClockDelegate::AnalogClockDelegate(QObject*)in AnalogClockDelegate.o 
ld: symbol(s) not found 
collect2: ld returned 1 exit status 
make: *** [Clock.app/Contents/MacOS/Clock] Error 1 
The process "/usr/bin/make" exited with code 2. 
Error while building project Clock (target: Desktop) 
When executing build step 'Make' 

ClockDelegate：

#ifndef CLOCKDELEGATE_H 
#define CLOCKDELEGATE_H 

#include <QObject> 

class QTime; 
class QWidget; 

class ClockDelegate : public QObject 
{ 
    Q_OBJECT 

public: 

    explicit ClockDelegate(QObject *parent); 

    virtual void paintClock(QWidget *, QTime *) = 0; 
}; 

#endif // CLOCKDELEGATE_H 

AnalogClockDelegate：

#ifndef ANALOGCLOCKDELEGATE_H 
#define ANALOGCLOCKDELEGATE_H 

#include <QColor> 
#include <QPoint> 

#include "ClockDelegate.h" 

class QWidget; 

class AnalogClockDelegate : public ClockDelegate 
{ 
    Q_OBJECT 

public: 

    explicit AnalogClockDelegate(QObject *parent); 

    void paintClock(QWidget *, QTime *); 

private: 

    void setupClockHands(); 

    void drawClockSurface(QWidget *clockView, QTime *); 

    void drawHourComponent(QWidget *clockView); 

    void drawMinuteComponent(QWidget *clockView, QTime *); 

    void drawSecondComponent(QWidget *clockView, QTime *); 

    QPoint m_center; 
    QPoint m_hourHand[3]; 
    QPoint m_minuteHand[3]; 
    QPoint m_secondHand[2]; 

    QColor m_hourColor; 
    QColor m_minuteColor; 
    QColor m_secondColor; 
    QColor m_clockFaceColor; 
}; 

#endif // ANALOGCLOCKDELEGATE_H 

Answer 1

我想你错过了 “公共” 的关键字，假设ClockDelegate是一个QObject。否则，你不是从QObject派生的，所以你不能使用Q_OBJECT。

class AnalogClockDelegate : public ClockDelegate