QObject繼承不明確的基地

我有一個簡單的類，當我的程序獲得並失去焦點時停止並啓動一個計時器，但它給出的錯誤是QObject是MyApp在每個信號插槽連接上的模糊基礎。下面是相關代碼：QObject繼承不明確的基地

class MyApp : public QApplication, public QObject 
{ 
    Q_OBJECT 
    ... 
}

這裏是我的（凌亂）Main.cpp的：

#include <QtGui/QApplication> 
    #include "qmlapplicationviewer.h" 
    #include <QObject> 
    #include <QGraphicsObject> 
    #include <QTimer> 
    #include <QVariant> 
    #include "timecontrol.h" 
    #include "scorecontrol.h" 
    #include "Retry.h" 
    #include <QEvent> 
    #include "myapp.h" 

    int main(int argc, char *argv[]) 
    { 
     MyApp app(argc, argv); 

     QmlApplicationViewer viewer; 
     viewer.setOrientation(QmlApplicationViewer::ScreenOrientationLockLandscape); 
     viewer.setMainQmlFile(QLatin1String("qml/Raker/main.qml")); 
     viewer.showExpanded(); 

     QObject *rootObject = viewer.rootObject(); 

     QTimer *timmer = new QTimer; 
     timmer->setInterval(1000); 

     TimeControl *timcon = new TimeControl; 

     scorecontrol *scorer = new scorecontrol; 

     Retry *probeer = new Retry; 

     QObject::connect(timmer, SIGNAL(timeout()), timcon, SLOT(updateTime())); 
     QObject::connect(timcon, SIGNAL(setTime(QVariant)), rootObject, SLOT(setTime(QVariant))); 
     QObject::connect(rootObject, SIGNAL(blockClicked(int, int)), scorer, SLOT(checkRight(int, int))); 
     QObject::connect(scorer, SIGNAL(setScore(QVariant)), rootObject, SLOT(setScore(QVariant))); 
     QObject::connect(scorer, SIGNAL(setState(QVariant)), rootObject, SLOT(setState(QVariant))); 

     QObject::connect(rootObject, SIGNAL(start()), probeer, SLOT(Reetry())); 
     QObject::connect(probeer, SIGNAL(start()), timmer, SLOT(start())); 
     QObject::connect(probeer, SIGNAL(stop()), timmer, SLOT(stop())); 
     QObject::connect(probeer, SIGNAL(start(int)), scorer, SLOT(randomNum(int))); 
     QObject::connect(probeer, SIGNAL(sReset()), timcon, SLOT(reset())); 
     QObject::connect(probeer, SIGNAL(tReset()), scorer, SLOT(reset())); 
     QObject::connect(timcon, SIGNAL(timeOut()), scorer, SLOT(reset())); 

     QObject::connect(timcon, SIGNAL(setState(QVariant)), rootObject, SLOT(setState(QVariant))); 
     QObject::connect(timcon, SIGNAL(changeFinal()), scorer, SLOT(changeFinal())); 
     QObject::connect(scorer, SIGNAL(setFinal(QVariant)), rootObject, SLOT(setFinal(QVariant))); 

     QObject::connect(&app, SIGNAL(focusL()), probeer, SLOT(focusL())); 
     QObject::connect(&app, SIGNAL(focusG()), probeer, SLOT(focusG())); 

     return app.exec(); 
    }

MyApp.cpp中：

#include "myapp.h" 
    #include <QDebug> 
    #include <QObject> 

    MyApp::MyApp(int argc, char **argv): QApplication(argc, argv) 
    { 
     installEventFilter(this); 
    } 

    bool MyApp::eventFilter(QObject *object, QEvent *event) 
    { 
     if (event->type() == QEvent::ApplicationDeactivate) 
     { 
      qDebug() << "Focus lost"; 
      focusL(); 
     } 
     if (event->type() == QEvent::ApplicationActivate) 
     { 
      qDebug() << "Focus gained"; 
      focusG(); 
     } 

     return false; 
    }

來源

2011-10-26 Gerharddc

用你當前的例子，你已經創建了一個拆分繼承方案，其中你的對象以QObject的雙重實例結束...... QApplication有一個基地QObject，另一個用於實際的MyApp類。這會產生歧義，因爲訪問繼承的QObject方法或數據成員不會確切知道要訪問哪個繼承基礎對象。

現在，你的繼承圖看起來是這樣的（注意的QObject的兩個實例，你MyApp對象繼承）：

| QObject |   | QObject | 
     \    /
     \   | QApplication | 
     \   /
      \   /
     | MyApp |

您應該保留繼承圖線，而不是有一個分裂繼承方案，並這意味着有一個只包含一個基類實例的派生類。所以，你想是這樣的：

QObject 
     | 
     | 
    QApplication 
     | 
     | 
    MyApp

來源

2011-10-26 13:45:02 Jason

好吧，但是現在在Q_OBJECT宏上方的「{」上以及MyApp.cpp中這兩行上MyApp的兩次出現中獲得對'MyApp'的vtable的未定義引用：「MyApp :: MyApp（int argc，char ** argv）：QApplication（argc，argv）」 – Gerharddc

你的'main（）'看起來像什麼？ ...我也會首先在你的項目上再次發表Laurent關於運行'qmake'的評論。 – Jason

我已將我的主添加到我的qeustion中 – Gerharddc

QApplication已經是一個QObject，所以你應該簡單地寫：

class MyApp : public QApplication 
{ 
    Q_OBJECT 
... 

}

來源

2011-10-26 13:36:38

好了，但現在就在這行上MyApp的兩個OCCURENCES一個未定義的引用「虛函數表的MyApp的」對「{」上面的Q_OBJECT宏，在MyApp.cpp中：「MyApp :: MyApp（int argc，char ** argv）：QApplication（argc，argv）」 – Gerharddc

您是否首先在您的項目上運行qmake？ –

我使用Qt Creator，它似乎自動執行 – Gerharddc

QObject繼承不明確的基地

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