Qt connect signal slot twice

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I'm pretty much a beginner at Qt. Anyway, I'm trying to use signals and slots to show a widget once the button is pressed. I created the widget, and have the connect() thing all done, but what do I...

Qt Signals and Slot connected twice... what happens ... Usually bad things. It's perfectly acceptable to connect the slot twice or even more times but when the signal gets fired your slot will be called for each connection you made which is probably not what you want. Note that it is not necessarily wrong to have multiple connections. There are (probably) perfectly valid uses for it. Qt Signals and Slot connected twice... what happens ... A few weeks ago, we had an intern accidentally connect a signal to a slot more than once. The idea was that under one condition, you'd have the slot connected to the signal, and under another condition you'd disconnect it. When you changed modes, you'd do the appropriate work. Well, he forgot to to disconnect when appropriate. c++ - Why does this slot get called twice? - Stack Overflow Why does this slot get called twice? Ask Question 5. 0. My problem is that when I click on an item in a QMenuBar, the corresponding slot gets called twice. I'm using Qt 4.8.1. I'm not using Qt Designer nor the "auto-connection" feature. ... and it seems to me that they connect the triggered signal to some slot in a different way: while you ... How to Use Signals and Slots - 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 ) ) );

Connect QML Signal with C++ Slot | Qt Forum So, now what I think is better: You create one single object ("backend") that acts as the C++ interface to your business logic. The QtQuick GUI will only interact with the C++ part through that object. backend.h #ifndef BACKEND_H #define BACKEND_H #inclu... Qt DoubleSpin Box value changed slot has called twice | Qt ...

Qt. Как использовать сигналы-слоты? — Toster.ru

Why does this slot get called twice? ... the corresponding slot gets called twice. I'm using Qt 4.8.1. ... me that they connect the triggered signal to some slot in a ...

In my case I am a bit stuck as I am getting the editFinished signal twice even when my slot handler is doing nothing. For a test, I have an array of QLineEdit which use a signalMapper to connect the editingFinished() signals to a single slot. The signalMapper passes the array index so I can see where the signal came from. eg:

Hello, I have an application with a main widget (parentWidget). Within my main widget I create a new widget (we can call it childWidget). Within childWidget I create a new widget (call it grandchildWidget). I want to connect a signal from my grandchild to... Signals and Slots - Qt Documentation 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. QT : CONNECT - C++ Forum

Qt Signals and Slot connected twice... what happens? -…

New-style Signal and Slot Support — PyQt 4.11.4 Reference Guide