未定义对 vtable 的引用... Q_OBJECT 宏 [英] Undefined reference to vtable... Q_OBJECT macro
问题描述
当我取消注释信号槽所需的 Q_OBJECT 宏时，我得到一个未定义的对 MyApp 错误的 vtable 的引用，但没有宏它可以完美编译，但没有它我不能使用信号和槽.我想我可能做错了一些愚蠢的事情，但请尝试帮助，因为我真的找不到问题.O，我知道我的代码不整洁，并且正在处理它.
When I uncomment the Q_OBJECT macro that I need for signal-slot I get a undefined reference to vtable for MyApp error, but without the macro it compiles perfectly but I can't use signals and slots without it. I think I may be doing something stupid wrong, but please try helping because I realy can't find the problem. O and I know my code is untidy and am working on it.
myapp.h:
#ifndef MYAPP_H
#define MYAPP_H
#include <QApplication>
#include <QEvent>
#include <QObject>
#include <QDebug>
class MyApp : public QApplication
{
public:
MyApp( int argc, char** argv );
protected:
bool eventFilter(QObject *object, QEvent *event);
signals:
void focusG();
void focusL();
};
#endif // MYAPP_H
myapp.cpp:
#include "myapp.h"
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;
}
main.cpp:
#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[])
{
//QApplication app(argc, 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();
}
BlockToucher.pro:
BlockToucher.pro:
# Add more folders to ship with the application, here
folder_01.source = qml/Raker
folder_01.target = qml
DEPLOYMENTFOLDERS = folder_01
# Additional import path used to resolve QML modules in Creator's code model
QML_IMPORT_PATH =
symbian:TARGET.UID3 = 0x2004b49f
# Smart Installer package's UID
# This UID is from the protected range and therefore the package will
# fail to install if self-signed. By default qmake uses the unprotected
# range value if unprotected UID is defined for the application and
# 0x2002CCCF value if protected UID is given to the application
symbian:DEPLOYMENT.installer_header = 0x2002CCCF
# Allow network access on Symbian
symbian {
#TARGET.CAPABILITY += NetworkServices
vendorinfo = "%{"Gerhard de Clercq"}" ":"Gerhard de Clercq""
ICON = BlockToucher.svg
}
# If your application uses the Qt Mobility libraries, uncomment the following
# lines and add the respective components to the MOBILITY variable.
# CONFIG += mobility
# MOBILITY +=
# The .cpp file which was generated for your project. Feel free to hack it.
SOURCES += main.cpp
timecontrol.cpp
scorecontrol.cpp
Retry.cpp
myapp.cpp
myapplication.cpp
# Please do not modify the following two lines. Required for deployment.
include(qmlapplicationviewer/qmlapplicationviewer.pri)
qtcAddDeployment()
HEADERS +=
timecontrol.h
scorecontrol.h
Retry.h
myapp.h
myapplication.h
OTHER_FILES +=
qtc_packaging/debian_fremantle/rules
qtc_packaging/debian_fremantle/README
qtc_packaging/debian_fremantle/copyright
qtc_packaging/debian_fremantle/control
qtc_packaging/debian_fremantle/compat
qtc_packaging/debian_fremantle/changelog
compat
qtc_packaging/debian_fremantle/changelog
推荐答案
MOC 系统使用Q_OBJECT 来生成信号所需的代码.我最好的猜测是你的项目中没有包含 MOC 生成的文件(它生成的 CPP 文件).
Q_OBJECT is used by the MOC system to produce the code you need for the signals. My best guess would be that you are not included the MOC generated files in your project (the CPP files which it generates).
您如何执行此操作很大程度上取决于您的构建系统(CMake、QMake、AUtomake、MSVC)，但您应首先参考 QMake 教程.
How you do this greatly depends on your build system (CMake, QMake, AUtomake, MSVC) but you should refer to the tutorial with QMake first.
也就是说，对 vtable 的未定义引用是我有时在忘记更新我的 Cmake 文件并拥有 Q_OBJECT 时遇到的错误.
That is, the undefined reference to vtable is the error I sometimes get when I forget to update my Cmake files and have a Q_OBJECT.
另外，你的 MyApp 的 ctor 是错误的，签名必须是:
Also, your ctor for MyApp is wrong, the signature must be:
MyApp( int & argc, char** argv );
如果您使用命令行参数，& 很重要.
The & is important should you ever use command-line parameters.
这篇关于未定义对 vtable 的引用... Q_OBJECT 宏的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
