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why doesn't this connect() function work?



  • I want to use lambda expression in my function,the relations between files and classes like follows:

    //main.cpp
    MainWIndow w;
    w.show()
    
    //MainWIndow.h
    class MainWindow:public QMainWindow
    {
              void initMainWindowUI();
    }
    
    //MainWindow.cpp
    void MainWindow::initMainWIndowUI()
    {
       QAction *colors = new QAction(ui->menuEdit);
       // this connect() work well 
       connect(colors,&QAction::triggered,this,&MainWindow::doActionColorGradient);
       ui->menuEdit->addAction(colors);
    }
    void MainWindow::doActionColorGradient()
    {
       QSharedPointer<QDialog> colorGradientParamInputDlg(new QDialog());
       QColor firstColor;
       QToolButton *firstColorButton;
       firstColorButton = new QToolButton();
       // there is nothing happened when I clicked the firstColorButton.
       // what's wrong with my code?
       QObject::connect(firstColorButton,&QToolButton::triggered,[&]{
    
         firstColor = QColorDialog::getColor(QString("first color"));
    
       });
       
    }
    

    Appreciate if you can tell me the solutions .


  • Moderators

    You're using &QToolButton::toggled, but a thats not enabled by default.

    add the following below firstColorButton = new QToolButton()

    firstColorButton ->setCheckable(true);
    


  • Thank you,But it seems not effct,and I edit

    QObject::connect(firstColorButton,&QToolButton::triggered,...
    

    to

    QObject::connect(firstColorButton,&QPushButton::clicked,...
    

    then it works.
    And I'm learning the differences between triggered and clicked. XD


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