QSerialPort closed when access from another class

[Lesiok]

Can You show real code ? In the first post you showed some strange pieces of code that do not make sense.

[d_stranz]

If the original code fragment posted is part of the real code, then the line "MainWindow m;" is creating a new second instance of MainWindow on the stack and is trying to use the QSerialPort that was previously created and opened in the first MainWindow instance.

[Cazzaniga]

If the original code fragment posted is part of the real code, then the line "MainWindow m;" is creating a new second instance of MainWindow on the stack and is trying to use the QSerialPort that was previously created and opened in the first MainWindow instance.

I see.. so which should be the best way to call a method/function defined in another class without calling a second instance of that class (like I did before)?
Thank you!

[Lesiok]

You can pass the pointer of a QSerialPort object or use the signals and slots mechanism.