signals-slots

I am working on an application which uploads the content of the file to server. To upload the file to server I am using ‘QNetworkAccessManager’ class. Since it works as asynchronous way, I changed it to work as synchronous way by using QEventLoop. Class FileTransfer { Public : QNetworkAccessManager mNetworkManager; Void Upload(QNetworkRequest request, QIODevice *data) { responce = mNetworkManager.put(request, data); EventLoop.exec(); ReadResponce(responce); } Void Stop() { responce ->close(); } } In my sample application I have 2 windows. 1st to select the files and 2nd to show the progress.

According to the documentation the return value from a slot doesn't mean anything. Yet in the generated moc code I see that if a slot returns a value this value is used for something. Any idea what does it do? Here's an example of what I'm talking about. this is taken from code generated by moc. 'message' is a slot that doesn't return anything and 'selectPart' is declared as returning int. case 7: message((*reinterpret_cast< const QString(*)>(_a[1])),(*reinterpret_cast< int(*)>(_a[2]))); break; case 8: { int _r = selectPart((*reinterpret_cast< AppObject*(*)>(_a[1])),(*reinterpret_cast< int(*)>

I am wondering if i need to disconnect singals and slots if i destroy the signal emitting object. Here is an example: QAudioOutput * audioOutput = new QAudioOutput(format,mainWindow); connect(audioOutput,SIGNAL(stateChanged(QAudio::State)),this,SLOT(stateChanged(QAudio::State))); delete audioOutput; audioOutput = new QAudioOutput(format,mainWindow); connect(audioOutput,SIGNAL(stateChanged(QAudio::State)),this,SLOT(stateChanged(QAudio::State))); Will this automatically disconnect the signal from the old audioOutput, or will it lead to mem leaks or some other undefined behavior ? Thank you in

This question is already asked in this forum but I don't understand the concept. I was reading around and it seems that signal and slots are implemented using function pointers i.e the signal is one big function which inside it calls all connected slots (function pointers). Is this correct? And what is the role of the generated moc files in the whole story? I don't understand how the signal function knows which slots to call i.e which slots are connected to this signal. Thanks for your time P Shved Qt implements these things in a way that resembles interpreted languages. I.e. it constructs

The question is just done for educational purpose: Does the use of 30-50 or more pairs of signals and slots between two object (for example two threads) affect the application performance, runtime or response times? Kuba Ober First of all, you should probably not put any slots in QThreads. QThreads aren't really meant to be derived from other than by reimplementing the run method and private methods (not signals!). A QThread is conceptually a thread controller, not a thread itself. In most cases you should deal with QObjects. Start a thread, then move the object instance to that thread. That's

I understand how to use it, but the syntax of it bothers me. What is "private slots:" doing? I have never seen something between the private keyword and the : in a class definition before. Is there some fancy C++ magic going on here? And example here: #include <QObject> class Counter : public QObject { Q_OBJECT public: Counter() { m_value = 0; } int value() const { return m_value; } public slots: void setValue(int value); ... Russell Davis Slots are a Qt-specific extension of C++. It only compiles after sending the code through Qt's preprocessor, the Meta-Object Compiler (moc). See http://doc