I'm trying to connect a signal from a QProcess
inside my mainwindow()
object to another QObject
based class inside my mainwindow()
object but I get this error:
QObject::connect: Cannot connect (null)::readyReadStandardOutput () to (null)::logReady()
Heres the code, its not complete by any means but I don't know why it doesn't work.
exeProcess.h
#ifndef EXEPROCESS_H
#define EXEPROCESS_H
#include <QObject>
class exeProcess : public QObject
{
Q_OBJECT
public:
explicit exeProcess(QObject *parent = 0);
signals:
void outLog(QString outLogVar); //will eventually connect to QTextEdit
public slots:
void logReady();
};
#endif // EXEPROCESS_H
exeProcess.cpp
#include "exeprocess.h"
exeProcess::exeProcess(QObject *parent) :
QObject(parent)
{
}
void exeProcess::logReady(){
}
mainwindow.h
#ifndef MAINWINDOW_H
#define MAINWINDOW_H
#include <QMainWindow>
#include <QProcess>
#include "exeprocess.h"
/*main window ---------------------------------------*/
namespace Ui {
class MainWindow;
}
class MainWindow : public QMainWindow
{
Q_OBJECT
public:
explicit MainWindow(QWidget *parent = 0);
~MainWindow();
QProcess *proc;
exeProcess *procLog;
public slots:
private:
Ui::MainWindow *ui;
};
#endif // MAINWINDOW_H
mainwindow.cpp
#include "mainwindow.h"
#include "ui_mainwindow.h"
MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
ui->setupUi(this);
connect(proc, SIGNAL(readyReadStandardOutput ()), procLog, SLOT(logReady()));
}
MainWindow::~MainWindow()
{
delete ui;
}
Thanks!.
You need to create the proc
and procLog
objects.
You've only got pointers as class members, so you'll have to initialize those (with new
). connect
only works on live objects.