How to call a function from another cpp file

herculis

hello guys
i want to call a function in one cpp file from another cpp file.
and i have written this function to slot
Can anyone please help me in this

P.S. i have added header file of second file(where the function is) also in the first 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)@