#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::on_cal_clicked() { int a = ui->num1->value(); int b = ui->num2->value(); ui->answer->setText(QString::number(a+b)); }