Passing class reference object to another form class

russjohn834

Hi all,

i have a basic question.

I have a class instance which need to be passed to other classes being constructed tetra_grip_api api;

I did this in the main

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);

    tetra_grip_api api;

    api.openSerialPort();
    QObject::connect(api.serial, SIGNAL(readyRead()), &api, SLOT(readData()));

    Settings w(&api);

Also, I changed the constructor of the Settings as follows:

 Settings :: Settings ( tetra_grip_api api, QWidget *parent) : QMainWindow(parent)
    , ui(new Ui:: Settings )
{
...

connect(&api, &tetra_grip_api::tetraGripEvent,this, &Settings::eventHandler);

Here I get an error complaining:

main.cpp:21:18: error: no matching constructor for initialization of 'Settings'
settings.h:23:6: note: candidate constructor not viable: no known conversion from 'tetra_grip_api *' to 'tetra_grip_api' for 1st argument; remove &
settings.h:18:7: note: candidate constructor (the implicit copy constructor) not viable: no known conversion from 'tetra_grip_api *' to 'const Settings' for 1st argument

I dont understand what's happening, any idea?

Thanks

jsulm

@russjohn834 said in Passing class reference object to another form class:

Settings :: Settings ( tetra_grip_api api, QWidget *parent) : QMainWindow(parent)

You're passing by value (means copy!), not by reference. Pass a pointer:

Settings :: Settings ( tetra_grip_api *api, QWidget *parent) : QMainWindow(parent)

The error message says what is wrong.

russjohn834

Thank you @jsulm

Solved Passing class reference object to another form class