unresolved external symbol "public: static struct QMetaObject const staticMetaObject"

Christian Ehrlicher

apart from the really strange usage of reference and pointers to this reference which will likely not work, don't use 'long long' in signals and slots (or any other 'composed' type as e.g. unsigned int)

a_coder

@Christian-Ehrlicher which vaule i can use in signal and slots?

Christian Ehrlicher

@a_coder said in unresolved external symbol "public: static struct QMetaObject const staticMetaObject":

which vaule i can use in signal and slots?

How should I know which value you send through signals and slot. If you want which datatype then, as I already said, anything which consists of only one word to not confuse the moc compiler.

a_coder

@Christian-Ehrlicher i want to synchronized my countdown from two windows so i send the signal with the time remain in there.however, i don't think that will make the code error

JonB

@a_coder
@Christian-Ehrlicher has suggested you do not use a type written as e.g. long long as a signal parameter, as moc may not like it. I don't know, but I would try obeying his hint and change that to see if it helps.

a_coder

@JonB now i removed long long in signal and it will get that in Timer class but i still got some errors

Build started at 8:33 CH...
1>------ Build started: Project: project, Configuration: Debug x64 ------
1>Reading Qt configuration (E:/Qt/6.7.0/msvc2019_64/bin/qmake)
1>uic mainw.ui
1>uic workspace.ui
1>moc control.h
1>moc mainw.h
1>moc workspace.h
1>main.cpp
1>mainw.cpp
1>workspace.cpp
1>moc_control.cpp
1>moc_mainw.cpp
1>G:\project\project\control.h(77,7): error C2143: syntax error: missing ';' before '*'
1>(compiling source file 'x64/Debug/moc/moc_mainw.cpp')
1>G:\project\project\control.h(77,7): error C4430: missing type specifier - int assumed. Note: C++ does not support default-int
1>(compiling source file 'x64/Debug/moc/moc_mainw.cpp')
1>G:\project\project\control.h(77,14): error C2238: unexpected token(s) preceding ';'
1>(compiling source file 'x64/Debug/moc/moc_mainw.cpp')
1>G:\project\project\control.h(51,15): error C2061: syntax error: identifier 'Mainw'
1>(compiling source file 'x64/Debug/moc/moc_mainw.cpp')
1>G:\project\project\control.h(51,27): error C2612: trailing ')' illegal in base/member initializer list
1>(compiling source file 'x64/Debug/moc/moc_mainw.cpp')
1>G:\project\project\mainw.h(12,2): warning C4081: expected ')'; found 'string'
1>(compiling source file 'x64/Debug/moc/moc_mainw.cpp')
1>G:\project\project\x64\Debug\moc\moc_mainw.cpp(32,1): warning C4081: expected ')'; found 'string'
1>G:\project\project\x64\Debug\moc\moc_mainw.cpp(159,1): error C1004: unexpected end-of-file found
1>Done building project "project.vcxproj" -- FAILED.
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========
========== Build completed at 8:33 CH and took 11,009 seconds ==========

jsulm

@a_coder Please post current control.h and also mark the line 77 there

a_coder

@jsulm

#ifndef CONTROLER_H
#define CONTROLER_H

#include <qobject.h>
#include <qtimer.h>
#include <qobject.h>
#include "mainw.h"
#include "workspace.h"


class Timer :public QObject {
	Q_OBJECT
public:
	Timer(long long &timesetup, QObject* parent = nullptr)
		:QObject(parent)
		,counter(new QTimer)
	{
		timereaining = &timesetup;
		connect(counter, &QTimer::timeout, this, &Timer::sendupdate);
	}
	long long timeleft() { return *timereaining; }
	void start() {
		counter->setInterval(1000);
		counter->start();
	}
signals:
	void requestupdated();
	void timeout();
private slots:
	void sendupdate() {
		if (*timereaining <= 0) {
			emit timeout();
		}
		else {
			(*timereaining)--;
			emit requestupdated();
		}
	}
private:
	long long* timereaining;
	QTimer* counter;
};

class control :public QObject {
	Q_OBJECT
public:
	control(Timer* time, QObject* parent = nullptr):
		QObject(parent)
		,timer(time)
		, workspace(new Workspace(timer))
		, mainw(new Mainw(timer))
	{
		/*mainw = new Mainw(timer);
		workspace = new Workspace(timer);*/
	}
	~control() {
	}
	void start() {
		connect(mainw, &Mainw::change_gui, this, &control::changeto_workspace_slot);
		connect(workspace, &Workspace::change_gui, this, &control::changeto_mainw_slot);
		mainw->start();
	}
//signals:
	//void changeto_mainw();
	//void changeto_workspace();
private slots:
	void changeto_mainw_slot() {
		mainw->start();
		workspace->close();
	}
	void changeto_workspace_slot() {
		workspace->start();
		mainw->close();
	}
private:
	Timer* timer;
	Mainw* mainw; //line 77
	Workspace* workspace;
};
#endif // CONTROLER_H

sorry idk how to mark that

jsulm

@a_coder Please also post mainw.h

jsulm

@a_coder Btw. it is not a good idea to have more than one QObject based class in one header file - this can cause problems with moc tool.

a_coder

@jsulm i detached it before and these are my files
mainw.h

#ifndef MAINW_H
#define MAINW_H

#include <qmainwindow.h>
#include "ui_mainw.h"
#include "control.h"

class Timer;
class control;

class Mainw : public QMainWindow {
	Q_OBJECT
public:
	void start();
	Mainw(Timer* time, QWidget* parent = nullptr);
	~Mainw();
signals:
	void change_gui();
private:
	Ui::Main* ui;
	Timer* timer;
private slots:
	void updatetime();
	void toworkspace() {
		ui->pushButton->setDisabled(true);
		emit change_gui();
		this->close();
	}
};
#endif // !MAINW_H

workspace.h

#ifndef WORKSPACE_H
#define WORKSPACE_H

#include <qprocess.h>
#include <qmainwindow.h>
#include "ui_workspace.h"
#include "control.h"

class Timer;

class Workspace : public QWidget {
	Q_OBJECT
public:
	Workspace(Timer* time, QWidget* parent = nullptr);
	~Workspace();
	void start();
signals:
	void change_gui();
private:
	//store all processes the ui run in a vector
	std::vector<QProcess*> processes;
	Ui::workspace* ui;
	Timer* timer;
private slots:
	void updatetime();
	void goback();
};

#endif // WORKSPACE_H

JonB

@jsulm said in unresolved external symbol "public: static struct QMetaObject const staticMetaObject":

more than one QObject based class in one header file

I don't want to derail this thread, but spoke to @Chris-Kawa a while ago and we both agree we have done this for years with no problems. Maybe we just don't do something "unusual/naughty/complicated".

jsulm

@a_coder said in unresolved external symbol "public: static struct QMetaObject const staticMetaObject":

#include "control.h"

class Timer;
class control;

You have a circular dependency: mainw.h includes control.h and control.h includes mainw.h. This is not going to work. Since you only use Timer* in mainw.h and already have a forward declaration for it, the control.h include is not needed, remove it.

a_coder

@jsulm it worked, thanks