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Qt method call from another class?

  • I got two windows(two classes), one window that opens another when i click a button.

    then the user inputs something into the newly opened window and then transfer that information to the first window when a button is clicked

    The problem is I can't seem to send something to the second window so i can send the user input back to the main window. I read a few places that I should use Q_object but not really sure how that works

    I should mention that I am new to Qt and didn't know about the designer there is in qt creator before i was way to ahead with the program.

    Hope you have some ideas to how I can do this

    I should show the relevant code i have


    @MainWindow::MainWindow(QWidget *parent) :
    //alot of stuff not relevant right now creating different stuff
    changeProfile= new QPushButton("├Žndre valgte profil",this);
    profileList = new QComboBox(this);
    cProfile = new CreateProfile;

    void MainWindow::ProfileChange()
    file pfile(profileList->currentText().toStdString());
    string tempName =;


    void MainWindow::setProfileList(QString Pname_)
    bool found = 0;
    for (int i = 0;i<5;i++)
    if (Pname_ ==profileList->itemText(i))
    found = 1;
    if (found !=1)

    @CreateProfile::CreateProfile(QWidget *parent)
    //alot of other irrelevant stuff here
    saveP = new QPushButton("Save",this);
    void CreateProfile::saveProfile()
    temp = pName->text();
    file pFile(temp.toStdString());
    bool lights[2] = {light1->checkState(),light2->checkState()};
    if (temp.length() == 0)
    MessageBox(NULL,"Du har ikke skrevet noget navn ind\n Prov igen","Error",MB_ICONWARNING+MB_SETFOREGROUND);
    //call function setProfileList

    If that makes sence, If you need the .h file too i can show them also

    I need to call setProfileList from the mainwindow in the function saveprofile(there is in createprofile window) or if there is a way i can change the combobox in the wainwindow from the createprofile window?

  • Ok with some help i found out that

    @cProfile = new CreateProfile;@
    should be
    @cProfile = new CreateProfile(this);@

    and then i should be able to do


    but this is not working i get this error

    bq. error: C2039: 'setProfileList' : is not a member of 'QObject'

  • Lifetime Qt Champion

    Hi and welcome to devnet,

    This question has been asked many times lately, please search the forum.

    Anyway, for such a functionality, the common way is to use Signals & Slots. I would recommend that you take a look at Qt's documentation and examples has they show how to do it very well and will give you the basics to go on with your project

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