undefined reference to `Config::SingleLinkedList::staticMetaObject' and `vtable for Config::SingleLinkedList'

Limer

class ConfigBase : public QWidget, it has slots and signals, so Q_OBJECT is set in the code.

Now, class SingleLinkedList : public ConfigBase , it also has its own slots and signals, so Q_OBJECT is also set in the code. But i come across one problem.

error: undefined reference to `Config::SingleLinkedList::staticMetaObject'

error: undefined reference to `vtable for Config::SingleLinkedList'

collect2.exe:-1: error: error: ld returned 1 exit status

I googled many, but no use.

If you want all the project(it is a little project, but is not convenient to public), leave your email !

SGaist

Hi,

Did you add/remove the Q_OBJECT macro at some point ? If so you should re-run qmake or do a full rebuild.

Limer

@SGaist

I tried, no use.

aha_1980

@Limer said in undefined reference to `Config::SingleLinkedList::staticMetaObject' and `vtable for Config::SingleLinkedList':

class ConfigBase : public QWidget, it has slots and signals, so Q_OBJECT is set in the code.

Hello, is your class defined in a header or in a cpp file?

If it's in a header file, try deleting the whole build folder (make sure there are no Makefiles left, neither in the source nor in the build folder).

If the definition is in a cpp file, then you will have to include the generated .moc file your own by apppending something like #include "singlelinkedlist.moc" at the end of your cpp file.

Limer

@aha_1980

In a heaer file. I tried, but it doesn`t work.

joeQ

@Limer Hi, friend.

Dot forget to add Q_OBJECT in head of class.
run qmake again.

If not Ok, you could show some code in your post.

Limer

@joeQ

#ifndef CONFIG_BASE_H
#define CONFIG_BASE_H

#include <QPushButton>
#include <QSlider>
#include <QGridLayout>
#include <QGroupBox>

#define CONFIG_NAMESPACE_START namespace Config {
#define CONFIG_NAMESPACE_END   }

class ConfigBase : public QWidget
{
    Q_OBJECT

public:
    explicit ConfigBase(QWidget *parent = 0) : QWidget(parent)
    {
        groupBox1 = new QGroupBox(tr("Speed Control"));
        speedSlider = new QSlider(Qt::Horizontal, groupBox1);
        speedSlider->setMinimum(0);
        speedSlider->setMaximum(300);
        speedSlider->setValue(150);
        sliderLayout = new QVBoxLayout(groupBox1);
        sliderLayout->addWidget(speedSlider);

        groupBox2 = new QGroupBox(tr("Start && Pause"));
        startPushButton = new QPushButton(tr("Start"));
        pausePushButton = new QPushButton(tr("Pause"));
        resetPushButton = new QPushButton(tr("Reset"));
        startPushButton->setEnabled(true);
        pausePushButton->setEnabled(false);
        resetPushButton->setEnabled(false);
        pushButtonLayout = new QGridLayout(groupBox2);
        pushButtonLayout->addWidget(startPushButton, 0, 0, 1, 1);
        pushButtonLayout->addWidget(pausePushButton, 0, 1, 1, 1);
        pushButtonLayout->addWidget(resetPushButton, 1, 0, 1, 1);

        connect(startPushButton, SIGNAL(clicked(bool)), SLOT(start()));
        connect(pausePushButton, SIGNAL(clicked(bool)), SLOT(pause()));
        connect(resetPushButton, SIGNAL(clicked(bool)), SLOT(reset()));
    }

    ~ConfigBase()
    {}

public slots:
    void start()
    {
        startPushButton->setEnabled(false);
        pausePushButton->setEnabled(true);
        emit comboBoxEnabled(false);
    }

    void pause()
    {
        if (pausePushButton->text() == QString(QObject::tr("Pause")))
        {
            pausePushButton->setText(QObject::tr("Continue"));
            resetPushButton->setEnabled(true);
            emit comboBoxEnabled(true);
        }
        else
        {
            pausePushButton->setText(QObject::tr("Pause"));
            resetPushButton->setEnabled(false);
            emit comboBoxEnabled(false);
        }
    }

    void reset()
    {
        pausePushButton->setText(QObject::tr("Pause"));
        startPushButton->setEnabled(true);
        pausePushButton->setEnabled(false);
        resetPushButton->setEnabled(false);
        speedSlider->setValue(150);
        emit comboBoxEnabled(true);
    }

signals:
    void comboBoxEnabled(bool);

public:
    QPushButton *startPushButton;
    QPushButton *pausePushButton;
    QPushButton *resetPushButton;
    QSlider     *speedSlider;

protected:
    QGroupBox   *groupBox1;
    QGroupBox   *groupBox2;

private:
    QVBoxLayout *sliderLayout;
    QGridLayout *pushButtonLayout;
};

#endif // CONFIG_BASE_H

#ifndef CONFIG_SINGLE_LINKED_LIST
#define CONFIG_SINGLE_LINKED_LIST

#include <QCheckBox>
#include <QSpinBox>
#include <QTabWidget>
#include <QTextEdit>
#include "config_base.h"

CONFIG_NAMESPACE_START

class SingleLinkedList : public ConfigBase
{
    Q_OBJECT

public:
    explicit SingleLinkedList(ConfigBase *parent = 0) : ConfigBase(parent)
    {
        delete groupBox1;
        startPushButton->setEnabled(false);

        insertWidget      = new QWidget;
        insertPosGroupBox = new QGroupBox(tr("Position"));
        insertKeyGroupBox = new QGroupBox(tr("Key"));
        headCheckBox1     = new QCheckBox(tr("head"));
        tailCheckBox1     = new QCheckBox(tr("tail"));
        keyTextEdit1      = new QTextEdit;
        customSpinBox1    = new QSpinBox;
        keyTextEdit1->setPlaceholderText(tr("key text edit"));
        customSpinBox1->setRange(2, 10);
        QHBoxLayout *hBoxLayout1 = new QHBoxLayout(insertPosGroupBox);
        hBoxLayout1->addWidget(headCheckBox1);
        hBoxLayout1->addWidget(tailCheckBox1);
        hBoxLayout1->addWidget(customSpinBox1);
        QHBoxLayout *hBoxLayout2 = new QHBoxLayout(insertKeyGroupBox);
        hBoxLayout2->addWidget(keyTextEdit1);
        QVBoxLayout *vBoxLayout1 = new QVBoxLayout(insertWidget);
        vBoxLayout1->addWidget(insertPosGroupBox);
        vBoxLayout1->addWidget(insertKeyGroupBox);
        vBoxLayout1->setSpacing(20);

        findWidget       = new QWidget;
        findKeyGroupBox  = new QGroupBox(tr("Key"));
        keyTextEdit2     = new QTextEdit;
        keyTextEdit2->setPlaceholderText(tr("key text edit"));
        QHBoxLayout *hBoxLayout3 = new QHBoxLayout(findKeyGroupBox);
        hBoxLayout3->addWidget(keyTextEdit2);
        QVBoxLayout *vBoxLayout2 = new QVBoxLayout(findWidget);
        vBoxLayout2->addWidget(findKeyGroupBox);

        removeWidget      = new QWidget;
        removePosGroupBox = new QGroupBox(tr("By Position"));
        removekeyGroupBox = new QGroupBox(tr("or By Key"));
        headCheckBox3     = new QCheckBox(tr("head"));
        tailCheckBox3     = new QCheckBox(tr("tail"));
        customSpinBox3    = new QSpinBox;
        keyTextEdit3      = new QTextEdit;
        customSpinBox3->setRange(2, 10);
        keyTextEdit3->setPlaceholderText(tr("text edit"));
        QHBoxLayout *hBoxLayout4 = new QHBoxLayout(removePosGroupBox);
        hBoxLayout4->addWidget(headCheckBox3);
        hBoxLayout4->addWidget(tailCheckBox3);
        hBoxLayout4->addWidget(customSpinBox3);
        QHBoxLayout *hBoxLayout5 = new QHBoxLayout(removekeyGroupBox);
        hBoxLayout5->addWidget(keyTextEdit3);
        QVBoxLayout *vBoxLayout3 = new QVBoxLayout(removeWidget);
        vBoxLayout3->addWidget(removePosGroupBox);
        vBoxLayout3->addWidget(removekeyGroupBox);
        vBoxLayout3->setSpacing(20);

        tabWidget = new QTabWidget;
        tabWidget->addTab(insertWidget, tr("Insert"));
        tabWidget->addTab(findWidget, tr("Find"));
        tabWidget->addTab(removeWidget, tr("Remove"));

        mainVBoxLayout = new QVBoxLayout(this);
        mainVBoxLayout->addWidget(tabWidget);
        mainVBoxLayout->addWidget(groupBox2);
        mainVBoxLayout->setSpacing(30);

        connect(headCheckBox1, SIGNAL(stateChanged(int)), this, SLOT(slot1(int)));
        connect(tailCheckBox1, SIGNAL(stateChanged(int)), SLOT(slot2(int)));
        connect(headCheckBox3, SIGNAL(stateChanged(int)), SLOT(slot3(int)));
        connect(tailCheckBox3, SIGNAL(stateChanged(int)), SLOT(slot4(int)));
        connect(tabWidget, SIGNAL(currentChanged(int)), SLOT(tabChangedReset(int)));

    }

    ~SingleLinkedList()
    {}

public slots:
    void slot1(int state)
    {
        if (state == Qt::Checked)
        {
            tailCheckBox1->setCheckState(Qt::Unchecked);
            customSpinBox1->setValue(2);
            tailCheckBox1->setEnabled(false);
            customSpinBox1->setEnabled(false);
        }
        else
        {
            tailCheckBox1->setEnabled(true);
            customSpinBox1->setEnabled(true);
        }
    }

    void slot2(int state)
    {
        if (state == Qt::Checked)
        {
            headCheckBox1->setCheckState(Qt::Unchecked);
            customSpinBox1->setValue(2);
            headCheckBox1->setEnabled(false);
            customSpinBox1->setEnabled(false);
        }
        else
        {
            headCheckBox1->setEnabled(true);
            customSpinBox1->setEnabled(true);
        }
    }

    void slot3(int state)
    {
        if (state == Qt::Checked)
        {
            tailCheckBox3->setCheckState(Qt::Unchecked);
            customSpinBox3->setValue(2);
            tailCheckBox3->setEnabled(false);
            customSpinBox3->setEnabled(false);
        }
        else
        {
            tailCheckBox3->setEnabled(true);
            customSpinBox3->setEnabled(true);
        }
    }

    void slot4(int state)
    {
        if (state == Qt::Checked)
        {
            headCheckBox3->setCheckState(Qt::Unchecked);
            customSpinBox3->setValue(2);
            headCheckBox3->setEnabled(false);
            customSpinBox3->setEnabled(false);
        }
        else
        {
            headCheckBox3->setEnabled(true);
            customSpinBox3->setEnabled(true);
        }
    }

    void insertWidgetReset()
    {
        headCheckBox1->setCheckState(Qt::Unchecked);
        tailCheckBox1->setCheckState(Qt::Unchecked);
        customSpinBox1->setValue(2);
        headCheckBox1->setEnabled(true);
        tailCheckBox1->setEnabled(true);
        customSpinBox1->setEnabled(true);
        keyTextEdit1->clear();
    }

    void findWidgetReset()
    {
        keyTextEdit2->clear();
    }

    void removeWidgetReset()
    {
        headCheckBox3->setCheckState(Qt::Unchecked);
        tailCheckBox3->setCheckState(Qt::Unchecked);
        customSpinBox3->setValue(2);
        headCheckBox3->setEnabled(true);
        tailCheckBox3->setEnabled(true);
        customSpinBox3->setEnabled(true);
        keyTextEdit3->clear();
    }

    void tabChangedReset(int index)
    {
        startPushButton->setEnabled(false);

        switch (index)
        {
        case 0:
            insertWidgetReset();
            break;
        case 1:
            findWidgetReset();
            break;
        case 2:
            removeWidgetReset();
            break;
        }
    }

    void resetAll()
    {
        //insertWidgetReset(); //  jian cha yi xia
        findWidgetReset();
        removeWidgetReset();
        tabWidget->setCurrentIndex(0);

        reset();
        startPushButton->setEnabled(false);
    }

private:
    QVBoxLayout *mainVBoxLayout;

    QTabWidget  *tabWidget;
    QWidget     *insertWidget;
    QWidget     *findWidget;
    QWidget     *removeWidget;

    QGroupBox   *insertPosGroupBox;
    QGroupBox   *insertKeyGroupBox;
    QCheckBox   *headCheckBox1;
    QCheckBox   *tailCheckBox1;
    QSpinBox    *customSpinBox1;
    QTextEdit   *keyTextEdit1;

    QGroupBox   *findKeyGroupBox;
    QTextEdit   *keyTextEdit2;

    QGroupBox   *removePosGroupBox;
    QGroupBox   *removekeyGroupBox;
    QCheckBox   *headCheckBox3;
    QCheckBox   *tailCheckBox3;
    QSpinBox    *customSpinBox3;
    QTextEdit   *keyTextEdit3;
};

CONFIG_NAMESPACE_END

#endif // CONFIG_SINGLE_LINKED_LIST

joeQ

@Limer

Try include QWidget in ConfigBase head file.
and Try include QObject in SingleLinkedList head file.

run qmake again.

mrjj

Hi
The code is fine. Compiles here.
So if still complaining, then completely delete the build folder.

alt text

Limer

@joeQ

I tried, failed. this is all project : https://pan.baidu.com/s/1c2hNztm

Limer

@mrjj

I had deleted all build* file, but failed again and same errors. this is all project : https://pan.baidu.com/s/1c2hNztm

Paul Colby

Hi @Limer,

The problem appears to be that you have two SingleLinkedList classes. Although they are in two separate namespaces, for whatever reason (not sure its a bug, or a known limitation), QMake is only producing a moc file for one of them - if you rename either source file, the moc will be for the other.

I'd suggest you rename one of those classes.

Cheers.

mrjj

Hi
You have the file single_linked_list.h in two folders
moc seems them as one
NMAKE:-1: warning: U4004: too many rules for target 'debug\moc_single_linked_list.cpp'

so rename one of the files and it works. you can do it directly in project explorer and all
is changed correctly.

alt text

ahh @Paul-Colby beat me to it :)

Limer

@mrjj @Paul Colby

Thanks, it`s ok!

Important: Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

undefined reference to `Config::SingleLinkedList::staticMetaObject' and `vtable for Config::SingleLinkedList'