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

[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