Math with Qt



  • Gents;

    I have been working on adding two numbers using 2 Qlinedits and displaying the result on a Qlabel using a Qpushbutton. Once launched the .exe file crashes and shows no result: please find below my code for review, your advices are welcome.

    Cheers.

    my .h

    #ifndef MAINWINDOW_H
    #define MAINWINDOW_H
    
    #include <QMainWindow>
    #include <QSpinBox>
    #include <QLabel>
    #include <QLineEdit>
    
    namespace Ui {
    class MainWindow;
    }
    
    class MainWindow : public QMainWindow
    {
        Q_OBJECT
    
    public:
        explicit MainWindow(QWidget *parent = 0);
        ~MainWindow();
    
        void valueChanged (QString resultat);
    
    private slots:
        void on_pushButton_clicked();
    
    private:
        Ui::MainWindow *ui;
    QLineEdit *Input1;
    QLineEdit *Input2;
    QLabel *resultat;
    };
    
    #endif // MAINWINDOW_H
    

    my .cpp

    #include "mainwindow.h"
    #include "ui_mainwindow.h"
    
    MainWindow::MainWindow(QWidget *parent) :
        QMainWindow(parent),
        ui(new Ui::MainWindow)
    {
        ui->setupUi(this);
    }
    
    MainWindow::~MainWindow()
    {
        delete ui;
    }
    
    void MainWindow::valueChanged(QString)
    {
    
        ui->resultat->setText(QString::number(Input1->text().toInt() + Input2->text().toInt()));
    
    }
    void MainWindow::on_pushButton_clicked()
    {
       valueChanged("resultat");
    }
    


  • Hi! Input1 and Input2 point to nothing.


  • Moderators

    @Abderaouf

    Added code tags to your post.
    Wieland was faster to answer


  • Moderators

    @Abderaouf
    the variables Input1 and Input2 are never initialized, but you are accessing them.
    I guess you want the input fields from your ui file no?
    You should access them with ui->Input1



  • Thank you guys and lady. That was reallly helpful.


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