How to call a function from another cpp file

SGaist

Hi,

Please, take the time to look at Qt's documentation as well as search this forum, this question has been asked many times.

herculis

i didnt find any post related to this question
Please help

Ildar

Please, show some problem code.
Your function is class member?

herculis

Header.h

@
class ap
{
Q_OBJECT
public slot:
void open();
}

call.cpp
include header.h
{
class ap:: open()
{
}
}
@

on.cpp

@
include header.h
{
connect(openButton,SIGNAL(clicked), this, SLOT(open));
}
@

[edit: added missing coding tags @ SGaist]

herculis

its like signal(clicked),this,slot(open)

Ildar

Please, use tags for code.

Maybe you need something like?

@
// call.h
class call : public QObject
{
Q_OBJECT

explicit call(QObject *parent)

public slot:
void open();
}

// call.cpp
#include "call.h"
#include <qdebug.h>

call::call(QObject *parent): QObject(parent)
{}

call::open()
{
qDebug() << "CALL";
}

// on.h
#include "call.h"
class on : public QObject
{
Q_OBJECT
explicit on(QObject *parent)

signals:
void mySignal();

private:
call *m_call;
}

// on.cpp
on::on(QObject *parent): QObject(parent)
{
m_call = new call(this);

connect(this, &on::mySignal, m_call, &call::open);

emit mySignal();
}
@

herculis

I am geeting error at line 41
@m_call = new call(this);@
no instance of constructor
no appropriate default constructor available

Ildar

Sorry!) I updated my answer

herculis

what u updated ???

Ildar

See my above answer:

@
// call.h
class call : public QObject
{
Q_OBJECT

explicit call(QObject *parent)

public slot:
void open();
}
...@

herculis

i did what u suggested but its not working.Not getting any error but not working also.
plz help

herculis

@
Header.h
class ap
{
Q_OBJECT
public slot:
void open();
}

call.cpp
include header.h
{
class ap:: open()
{
}
}

on.h
include header.h
{
class on
private:
ap*m_call

}

on.cpp

include header.h
{

m_call = new ap(this);
connect(openButton,SIGNAL(clicked), m_call, SLOT(open));@

Ildar

Try rename file names: you must have 4 files:
call.h
call.cpp
on.h
on.cpp

And, please show to us all files acrtual contents, not pseudocode.

herculis

i added header file in the program but then also its not working i have to create instance, with this it will work i guess i did that also means i created one object of the class where the function is and put that object in connect command but its not working please help
can a one give me an exmaple or a link for "calling a function from other cpp file" so that i will get an idea how to do that.

Ildar

Just create new project (Test) and add there files:

@
// call.h
#ifndef CALL_H
#define CALL_H

#include <QObject>

class call : public QObject
{
Q_OBJECT

public:
explicit call(QObject *parent = 0);

public slots:
void open();
};

#endif // CALL_H@

@
// call.cpp
#include "call.h"
#include <qdebug.h>

call::call(QObject *parent): QObject(parent)
{}

void call::open()
{
qDebug() << "CALL";
}
@

@
// on.h
#ifndef ON_H
#define ON_H

#include <QObject>
#include "call.h"

class on : public QObject
{
Q_OBJECT

public:
explicit on(QObject *parent = 0);

signals:
void mySignal();

private:
call *m_call;
};

#endif // ON_H
@

@
// on.cpp
#include "on.h"

on::on(QObject *parent): QObject(parent)
{
m_call = new call(this);

connect(this, &on::mySignal, m_call, &call::open);

emit mySignal();
}
@

@
// main.cpp
#include "on.h"

int main(int argc, char *argv[])
{
on *myOn = new on();
}
@

@
// Test.pro
HEADERS +=
call.h
on.h

SOURCES +=
call.cpp
on.cpp
main.cpp
@

herculis

Thanks this works but in my code its not working dont know why
Thanks though.

herculis

i am getting error in my prog when i write
@m_call=new call (this)@
''that no instance of constructor''

Ildar

Simpify the code and show it.

herculis

ok now i know the problem when i define the class contructore it has arguments in it thats why i am not able to create object.Do you know any solution regrading this how can i create object of a class whose constructor has arguments like bool*a,QWidget parent = 0
means
@call(boola ,QWidget *parent = 0,QObject *parent)@

Ildar

Please, read books about C++ and Qt.