Qt Signal Slot Connect Lambda

I am trying to connect slots with lambda functions, but it's not working the way I expect. In the code below, I succeed in connecting the first two buttons correctly. For the second two, which I connect in a loop, this goes wrong. Someone before me had the same question (Qt - Connect slot with argument using lambda), but this solution doesn't work for me. I've been staring at my screen for a half hour, but I can't figure out how my code is different.

No that's not possible with way how signal-slot is implemented in Qt. Connect can be called from anywhere where two objects and signal and slot are available. Meta object (defined in file generated by moc) must be able to get pointer to the function declared as slot, to add pointer to table of events.

• @mrjj said in How to get the sender in a C lambda signal slot handler?: But what do you do when hook up multiple objects to same lambda slot? If they are all pointers just use =. The compiler will take care to capture all and nothing more than what you need.
• I believe the signal/slot mechanism has found its soul mate in C11 lambda functions. What’s this signal/slot thingy? If you don’t work in Qt you probably don’t care anyway but the fundamental communication mechanism between objects in the Qt framework is defined by signals (events that can be emitted) and slots (handlers for events).
• Connect QML signal to C11 lambda slot (Qt 5) 0. Signal/Slots with VIsual studio and Qt plugin. Qt5 Signal/Slot syntax w/ overloaded signal & lambda.
• Instead of creating lambda functions on the fly to deal with different signals, you may want to consider using a QSignalMapper to intercept the signals and send them to a statically-defined slot with an argument dependent on the source. The behavior of the function would then depend entirely on the source of the original signal.

Pressing the first two buttons yields 'Pushed button 1' and 'Pushed button 2', the other two both yield 'Pushed button False', although I expected 3 and 4.

Qt Signal Slot Connect Lambda Dot

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I also haven't understood the lambda mechanism completely. What exactly gets connected? A pointer to a function that is generated by lambda (with the parameter substituted in) or is the lambda function evaluated whenever the signal fires?