can not call function of different class

[JadeN001]

connection.h

#ifndef CONNECTION_H
#define CONNECTION_H

#include <QDialog>
#include<QTcpSocket>
#include"mainwindow.h"
#include"formclient.h"
namespace Ui {
class connection;
}
class MainWindow;
class connection : public QDialog
{
    Q_OBJECT

public:
    explicit connection(QWidget *parent = 0);
    ~connection();
    QTcpSocket *m_pclientsocket;
    void send_MsgToServer(QString msg);

private slots:
    void Read();
    void displayError(QAbstractSocket::SocketError socketerror);
    void on_pushButton_connect_clicked();

    void on_pushButton_send_clicked();

private:
    Ui::connection *ui;
    MainWindow *m;
};

#endif // CONNECTION_H

connection.cpp

#include "connection.h"
#include "ui_connection.h"
#include<QMessageBox>
connection::connection(QWidget *parent) :
    QDialog(parent),
    ui(new Ui::connection)
{
    ui->setupUi(this);

}

void connection::send_MsgToServer(QString msg)
{
    qDebug()<<"in sendmsgserver"<<m_pclientsocket;
    m_pclientsocket->write(msg.toStdString().c_str());
    qDebug()<<"message sended "<<msg;
}

formclient.h

#ifndef FORMCLIENT_H
#define FORMCLIENT_H

#include <QWidget>
#include"mydelegate.h"
#include"mainwindow.h"
#include"connection.h"
#include<QString>
namespace Ui {
class FormClient;
}
class mydelegate;
class connection;
class FormClient : public QWidget
{
    Q_OBJECT

public:
    explicit FormClient( QString name,QWidget *parent = 0);
    ~FormClient();
signals:
    void sendmsg(QString msg);
public slots:
    void on_pushButton_send_clicked();

private:
    Ui::FormClient *ui;
    mydelegate *delegate;
    connection *mw;
    QString C_name;
};

#endif // FORMCLIENT_H

formclient.cpp

FormClient::FormClient(QString name, QWidget *parent) :
    QWidget(parent),
    ui(new Ui::FormClient)
{
    ui->setupUi(this);
    delegate=new mydelegate(this);
    mw=new connection(this);
    C_name=name;
    ui->label_clientname->setText(C_name);
}

FormClient::~FormClient()
{
    delete ui;
}

void FormClient::on_pushButton_send_clicked()
{
    QString s = ui->textEdit_message->toPlainText().trimmed();
 
    QString send=C_name+":"+s;
       qDebug()<<s<<" "<<send;
      mw->send_MsgToServer(send);  "<- not working"

}

mw->send_MsgToServer(send); is not getting executed. It is may be issue of object "mw".But i dont know what exactly it is.

[koahnig]

@JadeN001

Did you do a rerun of qmake and a rebuild?

Your project might be ouit of sync.

Otherwise the best is touse the debugger and set a break point there.

Possibly you should have received a warning for the connect not possible.

[JadeN001]

@koahnig program runs properly. But when function send_MsgToServer called.It stopped working.

[JonB]

@JadeN001
You have several qDebug() messages, including 2 in send_MsgToServer(). Do you think it would help us if you told us which ones produced any output (or state that none did), or would you like us to guess?

[JadeN001]

@JonB none of the qDebug() of send_MsgToServer() function works. I mean send_MsgToServer() is not getting called.
And formclient() is called from delegate's create editor().Is there amy connection with issue?

[JonB]

@JadeN001
OK, so you do get the qDebug() in on_pushButton_send_clicked() but not the first one even in send_MsgToServer(), right?

[koahnig]

@JadeN001

If you are trying to do an auto-connect through Qt, there might be the parameter missing [see here](lhttps://doc.qt.io/qt-5/qabstractbutton.html#clicked .

Therefore, my hint that you might have received a warning on that.

Also when a program crashes under certain circumstances it is helpful to use the debugger.

[JadeN001]

@JonB yeah. because send_MsgToServer() is getting called.

[JonB]

@JadeN001
Do you have access to and know how to use a debugger, because that's what I would use?

[JadeN001]

@koahnig @JonB I Don't have that much idea about debugger. Is there any alternative solution ?

[jsulm]

@JadeN001 You should really learn to use a debugger. A debugger is one of the most important tools a programmer should use :-)

[JonB]

@JadeN001
As @jsulm has just said, learning to use a debugger will in the long-run be the best time you spent! Just do it soon.

In the meantime, in on_pushButton_send_clicked() just before you try to call mw->send_MsgToServer(send); I'd put in some more qDebug() statements which show some of the properties of your connection object via mw->.... You're looking to just verify that mw is indeed still pointing at some valid connection, just in case.....

[JadeN001]

@JonB @jsulm yeah I really appreciate your suggestion. I will start.
I have checked Value of object "mw" by qDebug(). and It returns proper object value.
something like this :

object :  connection(0x201c0350, name="connection")

I thought that might be the issue is ,the object was not being generated properly.But i was wrong.

[JonB]

@JadeN001
Assuming it really is as you say, and you really have rebuilt your code etc., and you are compiling for/viewing debug, and it's not crashing, it's going to be pretty hard to answer how the line mw->send_MsgToServer(send) could simply "not get executed", without a debugger....

One last thing I can think of, just in case. Your first line in send_MsgToServer() is:

qDebug()<<"in sendmsgserver"<<m_pclientsocket;

Just in case there's some problem serializing m_pclientsocket, temporarily change it to plain:

qDebug()<<"in sendmsgserver"

(I don't think there actually will have been an issue because I think you're only trying to print out the pointer here, but it's worth a try...)

[JadeN001]

@JonB yeah u r right. Here is problem in m_pClientsocket. Thank you for direct me. now, I am trying to solve socket problem

[JadeN001]

I have define m_pClientsocket in constructor of class
but it failed to access in send_MsgToServer().
because ,If I define in constuctor then when formclient class define the object on connection class

FormClient::FormClient(QString name, QWidget *parent) :
    QWidget(parent),
    ui(new Ui::FormClient)
{
    ui->setupUi(this);
    delegate=new mydelegate(this);
    mw=new connection(this);
 
}

At that time value of socket is getting changed.
So the changes it bu moving the

    m_pclientsocket= new QTcpSocket(this);

in to another main function.

 void connection::on_pushButton_connect_clicked()
{
    m_pclientsocket= new QTcpSocket(this);

    ui->textEdit_Sendname->clear();
   m_pclientsocket->connectToHost(ui->textEdit_IP->toPlainText(),quint16(ui->textEdit_Port->toPlainText().toInt()));
   if(m_pclientsocket->waitForConnected(1000)){
   qDebug()<<"connected"<<m_pclientsocket;
   ui->label_connection->setText("Connected to Server");
   }
}

send_MsgToServer() can not access it . where i am wrong.? what could be solution?

[JadeN001]

In send_MsgToServer(). the ans of

void connection::send_MsgToServer(QString msg)
{ 
qDebug()<<"in sendmsgserver"<<m_pclientsocket;
    m_pclientsocket->write(msg.toStdString().c_str());
    qDebug()<<"message sended "<<msg;
}

in sendmsgserver QApplication(0x22fe28)
QIODevice::write (QApplication): device not open

what it is indicating? How can be value of socket be like QApplication.

[SGaist]

Hi,

Why are you creating a new QTcpSocket each time you call on_pushButton_connect_clicked ?

[aha_1980]

And why are you using waitForConnected?

this cannot work. use signals&slots!

regards

[JadeN001]

@SGaist because the Problem i am facing :
if I called new QTcpSocket from constructor,then

FormClient::FormClient(QString name, QWidget *parent) :
    QWidget(parent),
    ui(new Ui::FormClient)
{
    ui->setupUi(this);
    delegate=new mydelegate(this);
    mw=new connection(this);
 
}

this class create QTcpSocket evety time when mw=new connection(this); called.
because of that the void connection::send_MsgToServer(QString msg)
get different value of QTcpsocket.

[JadeN001]

@aha_1980 yeah i will correct it.but my problem is still there.

[SGaist]

Currently, with the code you provided, it seems you already have an architectural problem.

Can you describe what you are exactly trying to build ?

[JadeN001]

@SGaist I am creating one QTableview on clientside.when ever client connected,one editor for chatting will create in that tableview.

If want to send message to John from this editor.but when i send message from particular editor the value of QtcpSocket i am getting is somthing like this "

in sendmsgserver QApplication(0x22fe28)
QIODevice::write (QApplication): device not open

connection.cpp is class where socket is created.
formclient.cpp is class of widgets of chatting.

[JadeN001]

Can anyone suggest me , have I worked in a proper way or not?