How to access ui of widget from another .cpp in QT C++

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Hi,

I have to call the widget function(registration) from another .cpp file called ApplicationWindow.cpp.

Widget.cpp

Void Widget::registration()
{
    qDebug()<<"In registration function";
    QString regid = ui->lineedit_regid->text;
    qDebug()<<"regid="<<regid;
    //  after calling some API
}

ApplicationWindow.cpp

Void ApplicationWindow::closeApp()
{
    Widget *obj = new Widget();
    obj->registration(); //from here I have to call registration function
}

In ApplicationWindow.h I have included Widget.h.

Here I am able to call the registration function from ApplicationWindow but unable to access ui means unable to read lineedit text. When I am printing regid it is printing empty(nothing).

So how to read this line edit text, can you please provide the solution for this.

What I have tried:

Widget.cpp

Void Widget::registration()
{
    qDebug()<<"In registration function";
    QString regid = ui->lineedit_regid->text;
    qDebug()<<"regid="<<regid;
    ///  after calling some API  /////
}

ApplicationWindow.cpp

void ApplicationWindow::closeApp()
{
    Widget *obj = new Widget(); 
    obj->registration();  // from here I have to call registration function

}

Posted 29-Apr-19 20:38pm

Member 13740197

Updated 29-Apr-19 21:21pm

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Rick York · Accepted Answer · 2019-04-29T21:22:00

You have to expose a public interface to the object you are interested in. Usually this is done through static methods of a single object. For example, there is usually only one main application window and it can have a static Get() method that returns a pointer to itself. That pointer can then be used to access other members of the object. You can do something similar - give the object that contains the control a static Get() member that returns a pointer to itself and then you can access the control if it is a public member or there is a method that returns a pointer to it.

-edit-

Here's an example:

C++

class MyWindow
{
public:
    static MyWindow * Get() { return m_pThis; }

protected:
    static MyWindow * m_pThis;
};

Now you can access a pointer to MyWindow from anywhere that includes MyWindow's header file. If your control is a public member then it is directly accessible. If not then you will need to provide an accesser method, like GetTheControl() or what ever.