Trying to use QProcess

[hybrid_snyper]

Hi again,

Just wondering if anyone would mind having a look at an issue I am having and maybe point out where I am going wrong.

I have created a simple widget with a push button it Qt Designer, I have created Signals and Slots, clicked() and process_started() respectively. I am trying to run another Qt application when the push button is pressed.

However I keep getting compile errors which I cannot seem to resolve, so hopefully a fresh pair of eyes may be able to assist.

mainwindow.cpp:19: error: ISO C++ forbids declaration of ‘process_started’ with no type
mainwindow.cpp:19: error: prototype for ‘int mainwindow:rocess_started()’ does not match any in class ‘mainwindow’
mainwindow.h:25: error: candidate is: void mainwindow:rocess_started()

class mainwindow : public QMainWindow
{
    Q_OBJECT
 
public:
    mainwindow();
    QProcess *process;
 
public slots:
    void process_started();

class mainwindow : public QMainWindow
{
    Q_OBJECT

public:
    mainwindow();
    QProcess *process;

public slots:
    void process_started();

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mainwindow::mainwindow()
{
    process = new QProcess();
    widget.setupUi(this);
}
 
mainwindow::process_started()
{
    process->start("./home/i386-qt-rss");
}

mainwindow::mainwindow()
{
    process = new QProcess();
    widget.setupUi(this);
}

mainwindow::process_started()
{
    process->start("./home/i386-qt-rss");
}

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int main(int argc, char *argv[])
{
    QApplication app(argc, argv);
    mainwindow w;
    w.show();
    return app.exec();
}

int main(int argc, char *argv[])
{
    QApplication app(argc, argv);
    mainwindow w;
    w.show();
    return app.exec();
}

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Thanks very much for having look.

HS

[spirit]

you forgot to add forward declaration for QProcess class

...
class QProcess;
class mainwindow : public QMainWindow
{
...
};

...
class QProcess;
class mainwindow : public QMainWindow
{
...
};

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[spirit]

also, you forgot to specify type for function

void mainwindow::process_started()
{
    process->start("./home/i386-qt-rss");
}

void mainwindow::process_started()
{
    process->start("./home/i386-qt-rss");
}

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[hybrid_snyper]

also, you forgot to specify type for function

void mainwindow::process_started()
{
    process->start("./home/i386-qt-rss");
}

void mainwindow::process_started()
{
    process->start("./home/i386-qt-rss");
}

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You know something, I am sitting here looking at some example code and I don't know how I missed that, once you pointed it out I gave my forehead a bloody hard slap.

Thanks very much.

[hybrid_snyper]

Just to add, this has now compiled, however I thought the app the process is linked to would have started and opened up. I can see that there hass been a thread created when I click the pushbutton but nothing appears on screen. Is this normal?

[spirit]

if you need call program in a new process use QProcess::startDetached. in this case you will see a separate window.

[hybrid_snyper]

So I take it once startDetached is called then the first application is not aware of the second, ie when the launched app has finished and has been cloased?

[spirit]

it depends on how it works.
if you need to know when this app will stopped then you should use QProcess::start and handle signals QProcess::started & QProcess::finished.