new Signal/Slot syntax with parent QWidget? | Qt Forum connect(parent,SIGNAL(send_pi(double)), this, SLOT(showPi(double))); It might work in your particular case but It has exactly the same general problem i.e. if the parent is not a Widget* there's no such signal and the connection won't work. The difference... Cannot connect signal and slot from different thread. | Qt ... After I created the socket, I try to connect QUdpSocket::readyRead with my own function readData() from another thread. When I initialize in the UDP constructor QObject with the default constructor with no arguments, the output result is, that the first connect works fine and I get data, the disconnect works fine, because I don't get anymore data, but the reconnect does not work anymore. connect signal from subclass to father's slot | Qt Forum Qt Development General and Desktop connect signal from subclass to father's slot connect signal from subclass to father's slot. This topic has been deleted. Only users with topic management privileges can see it. Josz. last edited by Josz . Hi, I have a method in MainWindow called debug. MainWindow contains an object called inputline and into inputLine, there is a QPushbutton called sendButton ... New Signal Slot Syntax - Qt Wiki
Signals and slots are loosely coupled: A class which emits a signal neither knows nor cares which slots receive the signal. Qt's signals and slots mechanism ensures that if you connect a signal to a slot, the slot will be called with the signal's parameters at the right time. Signals and slots can take any number of arguments of any type. They are completely type safe.
Qt Signals and Slots, Connecting and Disconnecting - Blogger Qt Signals and Slots, Connecting and Disconnecting Get link; ... MainWindow connects A to B by calling "connect(A,signal,B,slot)" that could be ... the parent of ... Qt - A Small Example | qt Tutorial qt documentation: A Small Example. Example. Signals and slots are used for communication between objects. The signals and slots mechanism is a central feature of Qt and probably the part that differs most from the features provided by other frameworks. Connect a complex signal from QML to Qt/de - Qt Wiki
Signals and slots are loosely coupled: a class which emits a signal neither knows nor cares which slots receive the signal. Qt's signals and slots mechanism ensures that if you connect a signal to a slot, the slot will be called with the signal's parameters at the right time. Signals and slots can take any number of arguments of any type.
Signals and slots are loosely coupled: a class which emits a signal neither knows nor cares which slots receive the signal. Qt's signals and slots mechanism ensures that if you connect a signal to a slot, the slot will be called with the signal's parameters at the right time. Signals and slots can take any number of arguments of any type. Mapping Many Signals to One - Qt Documentation Qt allows us to connect multiple signals to the same signal or slot. This can be useful when we provide the user with many ways of performing the same operation. Sometimes, however, we would like the slot to behave slightly differently depending on which widget invoked it. New Signal Slot Syntax - Qt Wiki Connecting in Qt 5. There are several ways to connect a signal in Qt 5. Old syntax. Qt 5 continues to support the old string-based syntax for connecting signals and slots defined in a QObject or any class that inherits from QObject (including QWidget) . connect( sender, SIGNAL( valueChanged( QString, QString ) ), receiver, SLOT( updateValue( QString ) ) ); Signals and slots Connect | Qt Forum with signals and slots. It can be a bit of a challenge to have pointers to both objects in same place but often the mainwindow is a good place. Note that its also ok to connect signal to signal. This can be used to surface some signals from inside a class to outside world. Like if you have a dialog with an TextEdit.
Qt - Calling widget parent's slots - Stack Overflow
How Qt Signals and Slots Work - Woboq Qt is well known for its signals and slots mechanism. But how does it work? In this blog post, we will explore the internals of QObject and QMetaObject and discover how signals and slot work under the hood. In this blog article, I show portions of Qt5 code, sometimes edited for formatting and brevity. qt - QObject::connect no such Slot (QML, C++ ... I'm trying to connect a QML signal to a C++ slot, but for some reason (probably me being stupid) QObject::connect fails to find the slot. I've tried to connect a simple void signal from qml to a void slot with no parameters. I've triple checked the method signature, and names (I was originally passing strings around, but for the sake of fixing ... Signals & Slots — Qt for Python Signals and slots are loosely coupled: A class which emits a signal neither knows nor cares which slots receive the signal. Qt’s signals and slots mechanism ensures that if you connect a signal to a slot, the slot will be called with the signal’s parameters at the right time. Signals and slots can take any number of arguments of any type.
Why I dislike Qt signals/slots (Originally posted on Sunday, February 19th, 2012.) I've created over a dozen small projects using Qt by now. Most of the time I think I might as well make use of Qt's signals/slots system -- I mean it's already there.
Signals and slots are loosely coupled: A class which emits a signal neither knows nor cares which slots receive the signal. Qt's signals and slots mechanism ensures that if you connect a signal to a slot, the slot will be called with the signal's parameters at the right time. Signals and slots can take any number of arguments of any type. They are completely type safe. qt - connecting signal/slot across different threads ... I wanted to know what is the best practice to connect signal/slots between two QObjects created in the contructor of MainWindow but moved to different threads later...default connections seems not working then when I connect with the option Qt::Directconnection things start working...but sometimes the signal/slot fails...following is my code ... qt - How to connect a qml child component signal to a c++ ... I want to connect a child item component signal to a c++ slot but it is not working. I have one file ButtonItem.qml in which the code is like Item { id: button property string label new Signal/Slot syntax with parent QWidget? | Qt Forum connect(parent,SIGNAL(send_pi(double)), this, SLOT(showPi(double))); It might work in your particular case but It has exactly the same general problem i.e. if the parent is not a Widget* there's no such signal and the connection won't work. The difference...
Signals & Slots | Qt 4.8 Signals and slots are loosely coupled: A class which emits a signal neither knows nor cares which slots receive the signal. Qt's signals and slots mechanism ensures that if you connect a signal to a slot, the slot will be called with the signal's parameters at the right time. Signals and slots can take any number of arguments of any type. They are completely type safe. qt - connecting signal/slot across different threads ... I wanted to know what is the best practice to connect signal/slots between two QObjects created in the contructor of MainWindow but moved to different threads later...default connections seems not working then when I connect with the option Qt::Directconnection things start working...but sometimes the signal/slot fails...following is my code ...