Widget Set Value to an Object then Update the Value to Another Widget

[mimamrafi]

Hi everyone, I have a question. This is my goals schema

Example : I want to set value from widget 'a' and update the value in object, then I call the updated values from other widget

This is the first widget :

//maingui.h
...
#include "serialreadwrite.h"
public :
    void settingValue ();
...
private:
    Ui::MainGUI *ui;
    SerialReadWrite serialRW;

//maingui.cpp
void MainGUI::settingValue ()
{
...
serialRW.setValue(5);
}

This is the object class :

//serialreadwrite.h
class SerialReadWrite : public QObject
{
public:
    void setValue(int value);
    int getValue();
private :
    int currentValue = 0;

//serialreadwrite.cpp
void SerialReadWrite::setValue(int value)
{
    currentValue = value;
}

int SerialReadWrite::getValue()
{
    return currentValue;
}

this is the second widget (another widget)

//channelframe.h
#include "serialreadwrite.h"
public :
    void gotVal();
...
private:
    Ui::ChannelFrame *ui;
    SerialReadWrite serialRW;

//channelframe.cpp
void ChannelFrame::gotVal()
{
    qDebug () << serialRW.getValue();   //The values I got is 0, not 5 :(
}

However, I still get 0 (it's like I make new QObject again). I'm sorry for my little knowledge. is there any clues for my issues ? Thankyou for your help

[JonB]

@mimamrafi
You have two instances of SerialReadWrite serialRW, one in maingui and another in channelframe. These are not related, they are not the same object/instance. ("it's like I make new QObject again" --- indeed you do!) If they are supposed to be you need to create a unique instance somewhere and refer to that same instance elsewhere.

[jsulm]

@mimamrafi said in Widget Set Value to an Object then Update the Value to Another Widget:

SerialReadWrite serialRW;

You have two different SerialReadWrite instances in your classes which do not have anything to do with each other.
You should use signals/slots in Qt applications: class A emits a signal if the value is changed. This signal is connect to a slot in Object class, in that slot you can also emit a signal and connect a slot from class B to it. This way you have a flexible architecture: you can have many connections between class A nad Object class and also many connections between Object class and class B.