Getting QProcess to send Signals...

[ModelTech]

I have created a QWizardPage class, which has the following code in its constructor:

    Process = new QProcess(this);
    connect(Process, SIGNAL(stateChanged(QProcess::ProcessState)), this, SLOT(onRunning(QProcess::ProcessState)));
    connect(Process, SIGNAL(readyReadStandardOutput()), this, SLOT(onOutput()));
    connect(Process, SIGNAL(readyReadStandardError()), this, SLOT(onError()));

I have overriden the QWizardPage::initializePage() function and the code of my version of this function includes the following line:

Process->startDetached(Command);

where Command is QString that represents what should be executed. I see that this execution does take place and it does produce some text on stdout. However, none of the signals QProcess::stateChanged(QProcess::ProcessState), QProcess::readyReadStandardOutput() and QProcess::readyReadStandardError() get triggered as the slots in my QWizardPage to which these signals are connected do not get executed when the Command is executed. Is there anything that I should do to activate the signalling or so?

[SGaist]

Hi,

startDetached is a static method thus it doesn't use the Process object at all. Use start if you want to get something from your process.

[ModelTech]

Great! That solved it. Wasn't aware that startDetached is static...

[SGaist]

Well, the method documentation as well as QProcess's list of static methods are pretty clear.

However, with Qt 5.10, there will be a new version of that method.