How can I connect signals and slots of different objects in Qt?

Question

i have a doubt in QT c++

Suppose this is the main.cpp

#include \"head.h\"
#include \"tail.h\"

int main()
{
  head *head_obj = new head();
  tail *ta         


        

Answer 1

You connect signals and slots of instances, not of classes.

You need the address of both the receiver and the emitter objects to connect them together.

connect(button, SIGNAL(clicked()),
        pointer_to_instance_of_head, SLOT(change_number()));

(assuming "button" is a pointer).

Getting that pointer is another question, but unless you don't have a good reason to do otherwise, I suggest constructing the head object in the constructor of the QWidget you are deriving.

Answer 2

Well, assuming everything is as simple as you show it your really really abbriated code, it should be simple

connect( aTailInstance->tailButon, SIGNAL( clicked() ), aHeadInstance, SLOT( change_number() ) );

However, with the code you have shown here it is impossible to determine what kind of functionality you are after and it isn't clear exactly what you are asking.